Effect of off-pump and on-pump coronary artery bypass grafting on renal function. Off-pump coronary artery bypass surgery is associated with reduced neutrophil activation as measured by the expression of CD11b: a prospective randomized study. Effects of cardiopulmonary bypass on glucose homeostasis after coronary artery bypass surgery. Beating versus arrested heart coronary revascularization: evaluation by cardiac troponin I release. Off-pump coronary artery bypass surgery technique for total arterial myocardial revascularization: a prospective randomized study. A prospective, randomized study of endothelin and postoperative recovery in off-pump versus conventional coronary artery bypass surgery. Three-year follow-up in a subset of high-risk patients randomly assigned to off-pump versus on-pump coronary artery bypass surgery: the Best Bypass Surgery trial. Effects of on- and off-pump coronary artery surgery on graft patency, survival, and health-related quality of life: long-term follow-up of 2 randomized controlled trials. A randomized comparison of off-pump and on-pump multivessel coronary-artery bypass surgery. Assessment of neurocognitive impairment after off-pump and on-pump techniques for coronary artery bypass graft surgery: prospective randomised controlled trial. Randomized trial comparing off-pump to on-pump coronary artery bypass grafting in high-risk patients. Off-pump bypass graft operation significantly reduces oxidative stress and inflammation. Off-pump versus on-pump coronary artery surgery. A prospective randomized study to evaluate the renoprotective action of beating heart coronary surgery in low risk patients. Off-pump versus on-pump--intermittent aortic cross clamping--myocardial revascularisation: single center expirience. Expression of CD97 and adhesion molecules on circulating leukocytes in patients undergoing coronary artery bypass surgery. Comparison of inflammatory response following coronary revascularization with or without cardiopulmonary bypass. The long pentraxin 3 in cardiac surgery: distinct responses in "on-pump" and "off-pump" patients. Oxidative stress is decreased in off-pump versus on-pump coronary artery surgery. Reduced expression of systemic proinflammatory cytokines after off-pump versus conventional coronary artery bypass grafting. Off-pump coronary bypass operations significantly reduce S100 release: an indicator for less cerebral damage? Different CABG methods in patients with chronic obstructive pulmonary disease. Effect of off-pump coronary surgery with right ventricular assist device on organ function and inflammatory response: a randomized controlled trial. Off-pump versus on-pump myocardial revascularization in patients with ST-segment elevation myocardial infarction: a randomized trial. Myocardial revascularization with miniaturized extracorporeal circulation versus off pump: Evaluation of systemic and myocardial inflammatory response in a prospective randomized study. Comparison of inflammatory responses after off-pump and on-pump coronary surgery using surface modifying additives circuit. Myocardial injury in coronary artery bypass grafting: on-pump versus off-pump comparison by measuring high-sensitivity C-reactive protein, cardiac troponin I, heart-type fatty acid-binding protein, creatine kinase-MB, and myoglobin release. Early outcome of a randomized comparison of off-pump and on-pump multiple arterial coronary revascularization. Oxygenation and release of inflammatory mediators after off-pump compared with after on-pump coronary artery bypass surgery. A prospective randomized study to evaluate splanchnic hypoxia during beating-heart and conventional coronary revascularization. Endothelial apoptosis and circulating endothelial cells after bypass grafting with and without cardiopulmonary bypass. Early graft patency after off-pump and on-pump coronary bypass surgery: a prospective randomized study. Interleukin-1, interleukin-6 and myocardial enzyme response after coronary artery bypass grafting - a prospective randomized comparison of the conventional and three minimally invasive surgical techniques. Higher levels of serum cytokines and myocardial tissue markers during on-pump versus off-pump coronary artery bypass surgery. Neurocognitive outcomes of off-pump versus on-pump coronary artery bypass: a prospective randomized controlled trial. Value of delayed-enhancement cardiovascular magnetic resonance imaging in predicting myocardial viability after surgical revascularization. Myocardial metabolism on off-pump surgery; a randomized study of 50 cases. Neuropsychologic and quality-of-life outcomes after coronary artery bypass surgery with and without cardiopulmonary bypass: a prospective randomized trial. Isoprostanes and oxidative stress in off-pump and on-pump coronary bypass surgery. A prospective randomized study to evaluate the renal impact of surgical revascularization strategy in diabetic patients. Activation of the coagulation system during coronary artery bypass grafting: comparison between on-pump and off-pump techniques. Effect of off-pump coronary artery bypass surgery on clinical, angiographic, neurocognitive, and quality of life outcomes: randomised controlled trial. Risk of retinal microembolism after off-pump and on-pump coronary artery bypass surgery. Platelet activity and aspirin efficacy after off-pump compared with on-pump coronary artery bypass surgery: results from the prospective randomized trial PRAGUE 11-Coronary Artery Bypass and REactivity of Thrombocytes (CABARET). Relationship between atrial histopathology and atrial fibrillation after coronary bypass surgery. Effects of on-pump versus off-pump coronary artery bypass graft surgery on right ventricular function. Complete revascularization in coronary artery bypass grafting with and without cardiopulmonary bypass. Inflammatory response and myocardial injury following coronary artery bypass grafting with or without cardiopulmonary bypass. Surgical myocardial revascularization (CABG) in patients with pulmonary disease: beating heart versus cardiopulmonary bypass. Does off-pump coronary artery bypass surgery reduce secretion of plasminogen activator inhibitor-1? Myocardial metabolism assessed by microdialysis: a prospective randomized study in on- and off-pump coronary bypass surgery. Patterns of postoperative systemic vascular resistance in a randomized trial of conventional on-pump versus off-pump coronary artery bypass graft surgery. Health-related quality of life outcome after on-pump versus off-pump coronary artery bypass graft surgery: a prospective randomized study. Prospective randomized comparison of coronary bypass grafting with minimal extracorporeal circulation system (MECC) versus off-pump coronary surgery. Off-pump versus on-pump myocardial revascularization in low-risk patients with one or two vessel disease: perioperative results in a multicenter randomized controlled trial. Off-pump CABG reduces complement activation but does not significantly affect peripheral endothelial function: a prospective randomized study. S100 protein and its relation to cerebral microemboli in on-pump and off-pump coronary artery bypass surgery. Reduction of the inflammatory response in patients undergoing minimally invasive coronary artery bypass grafting. Coronary artery bypass grafting with or without cardiopulmonary bypass in patients with preoperative non-dialysis dependent renal insufficiency: a randomized study. Splanchnic organ injury during coronary surgery with or without cardiopulmonary bypass: a randomized, controlled trial. Five-year follow-up of a randomized comparison between off-pump and on-pump stable multivessel coronary artery bypass grafting. The MASS III Trial. Off-pump vs conventional coronary artery bypass grafting: early and 1-year graft patency, cost, and quality-of-life outcomes: a randomized trial. Neuromonitoring and neurocognitive outcome in off-pump versus conventional coronary bypass operation. One-year coronary bypass graft patency: a randomized comparison between off-pump and on-pump surgery angiographic results of the PRAGUE-4 trial. Pulmonary abnormalities after coronary arterial bypass grafting operation: cardiopulmonary bypass versus mechanical stabilization. Myocardial preservation during coronary surgery with and without cardiopulmonary bypass. The role of tissue factor and P-selectin in the procoagulant response that occurs in the first month after on-pump and off-pump coronary artery bypass grafting. Impact of cardiopulmonary bypass on peripheral tissue metabolism and microvascular blood flow. Comparison of the early results of coronary artery bypass grafting with and without extracorporeal circulation. Clinical and radiologic outcome of off-pump coronary surgery at 12 months follow-up: a prospective randomized trial. On-pump versus off-pump coronary-artery bypass surgery. Retinal and cerebral microembolization during coronary artery bypass surgery: a randomized, controlled trial. Systemic inflammation after on-pump and off-pump coronary bypass surgery: a one-month follow-up. Benefits of off-pump bypass on neurologic and clinical morbidity: a prospective randomized trial. Oxygen metabolism during and after cardiac surgery: role of CPB. Off-pump coronary artery bypass grafting does not reduce lymphocyte activation. Predictors of gastrointestinal complications after conventional and beating heart coronary surgery. Effects of cell saver autologous blood transfusion on blood loss and homologous blood transfusion requirements in patients undergoing cardiac surgery on- versus off-cardiopulmonary bypass: a randomised trial. Hemostasis in off-pump compared to on-pump coronary artery bypass grafting: a prospective, randomized study. Cognitive and cardiac outcomes 5 years after off-pump vs on-pump coronary artery bypass graft surgery.
Coronary artery bypass grafting (CABG) with cardiopulmonary bypass (CPB) has the risk of renal dysfunction. The cause of renal dysfunction after CPB is multifactorial, such as nonpulsatile flow, renal hypoperfusion, hypothermia, and duration of CPB. This study compared off-pump technique with on-pump technique on renal function in patients who underwent CABG.
                Sixty patients with normal preoperative renal functions undergoing CABG were randomly assigned to conventional revascularization with CPB (on-pump) or beating heart revascularization (off-pump). Renal functions were assessed up to 10 days postoperatively.
                Creatinine clearance was found to be significantly higher in the off-pump group than in the on-pump group (p<.05). The off-pump group had significantly less increase in creatinine levels when compared with the on-pump group (p<.05). The free water clearance values decreased similarly in both groups; however, the recovery was more prompt in the off-pump group (p<.05). No significant differences were found in the prevalence of postoperative hemodialysis.
                The off-pump technique may provide a positive contribution and sufficient protection on postoperative renal functions in patients undergoing CABG. Coronary artery bypass grafting (CABG) surgery is associated with systemic inflammation. Activation of neutrophils is a crucial step in inflammation and results in neutrophil sequestration within the tissues. One of the potential advantages of performing off-pump coronary artery bypass (OPCAB) surgery is the attenuation of the systemic inflammatory response. This prospective randomized study compares neutrophil activation in patients undergoing OPCAB versus those undergoing CABG with cardiopulmonary bypass (CPB).
                Twenty patients undergoing primary isolated CABG were randomly divided prospectively into 2 groups: 1 group underwent CABG with CPB, and the other group underwent OPCAB. Central venous blood samples were obtained before skin incision and at 15 minutes, 60 minutes, 2 hours, 5 hours, and 24 hours following the initiation of CPB or application of the stabilization device. Differential white cell counts were measured with routine laboratory techniques. CD11b surface expression on neutrophils was measured by flow cytometry. Interleukin 8 levels in the plasma were measured by enzyme-linked immunosorbent assays.
                The 2 groups were matched with respect to preoperative and operative characteristics. White cell and neutrophil counts rose in both groups following the operation but were significantly higher in the OPCAB group at 5 hours (P < .001 and P = .002, respectively). Interleukin 8 concentrations were significantly higher in the CPB group at 5 hours following the initiation of CPB (P = .034). CD11b levels were significantly higher in the CPB group at 60 minutes (P = .002).
                This prospective randomized study demonstrates that the activation of circulating neutrophils as measured by CD11b expression is lower following OPCAB than in CPB. Although OPCAB is associated with significantly higher neutrophil counts, these neutrophils exhibit fewer activation markers. The lower postoperative neutrophil counts occurring in the CPB group may be explained by the activation and consequent sequestration of the neutrophils in the CPB circuit and tissues. Hyperglycaemia is associated with increased mortality and morbidity after cardiac surgery. While surgical stress results in hyperglycaemia after all operations, it has been suggested that cardiopulmonary bypass is the dominating contributor after cardiac surgery. This study aimed to determine the contribution of cardiopulmonary bypass to hyperglycaemia after coronary artery bypass.
                Patients scheduled for primary coronary artery bypass grafting were randomised to surgery with or without cardiopulmonary bypass. All patients received continuous insulin infusions during the initial 24-h period. Glucose was infused (100mg/kg per h) postoperatively in the intensive care unit but not during surgery. Blood glucose was measured 4 times daily until the third postoperative day. Serum insulin, insulin-like growth factor-1 and its binding protein were determined.
                Average blood glucose during the day of surgery did not differ between groups, but 30% more insulin (P=0.003) was required when cardiopulmonary bypass was used. Blood glucose 2-3h after meals was higher in patients using cardiopulmonary bypass during the first 3 postoperative days. Fasting blood glucose was still equally elevated 20-30% in both groups on the third postoperative day. Insulin-like growth factor-1 decreased more (P=0.01) and insulin-like growth factor binding protein-1 increased more (P<0.001) with cardiopulmonary bypass than without. The ratio of insulin-like growth factor-1 concentration to the concentration of its binding protein-1 was more negative (indicating greater catabolism) with cardiopulmonary bypass than without both postoperatively (P=0.002) and on the third postoperative day (P=0.02). Insulin-like growth factor-1 standard deviation score, also a measure of catabolism, was greater after surgery with cardiopulmonary bypass than without (P=0.02).
                Glucose homeostasis is disturbed preoperatively for many non-diabetic patients undergoing coronary bypass surgery. Cardiopulmonary bypass exacerbates the catabolism and disturbed glucose homeostasis that is induced also to a lesser degree by surgery without cardiopulmonary bypass. This prospective randomized study aimed to compare beating and arrested heart revascularization in patients undergoing first elective coronary artery bypass graft, with cardiac troponin I release used to evaluate myocardial injury.
                Seventy patients were randomly assigned to a beating or arrested heart revascularization group. Cardiac troponin I concentrations were measured in serial venous blood samples drawn preoperatively in both groups: after aortic unclamping at 6, 9, 12, and 24 hours in the arrested heart group and after the last anastomosis at 6, 9, 12, and 24 hours in the beating heart group. Analysis of covariance with repeated measures was performed to test the effect of group and time on cardiac troponin I concentration.
                The total amount of cardiac troponin I released was higher in the arrested heart revascularization group than in the beating heart revascularization group (8.25 +/- 6.16 vs 3.18 +/- 4.75 microg, p < 0.0001). Cardiac troponin I concentrations were significantly higher in the arrested heart group at hours 6, 9, 12, and 24 than in the beating heart group (p < 0.0001).
                The lower release of cardiac troponin I in the beating heart revascularization group indicates that conventional coronary artery bypass graft with cardioplegic arrest causes more damage to the heart than off-pump myocardial revascularization. We investigated whether off-pump coronary artery bypass (OPCAB) surgery should be the procedure of choice in total arterial myocardial revascularization with composite grafts.
                We prospectively enrolled 176 patients undergoing total arterial myocardial revascularization and assigned them at random to one of two groups: group 1 was composed of 88 patients undergoing coronary surgery with cardiopulmonary bypass (CPB); group 2 consisted of 88 patients receiving the OPCAB procedure. We excluded from this study patients with significant risk factors for CPB-related morbidity. Composite arterial grafts in Y-T shape were realized in three different configurations according to patients' characteristics, coronary anatomy, and target stenosis.
                There were no significant differences between the two groups in terms of preoperative characteristics and risk factors (Euroscore: group 1 = 6.1 +/- 3.5, group 2 = 6.6 +/- 3.8). Mean number of anastomoses was similar in both groups (group 1 = 2.8 +/- 0.8, group 2 = 2.7 +/- 0.5) whereas mean mechanical ventilation time (group 1 = 23 +/- 9 hours, group 2 = 9 +/- 4 hours), intensive care unit stay (group 1 = 43 +/- 6 hours, group 2 = 22 +/- 8 hours), and postoperative stay (group 1 = 7 +/- 3 days, group 2 = 5 +/- 2 days) were significantly reduced in group 2. Early mortality was 2.3% in group 1 and 3.4% in group 2 (p = not significant). Major postoperative complications occurred similarly in the two groups (atrial fibrillation: group 1 = 35.2%, group 2 = 21.6%; myocardial infarction: group 1 = 2.2%, group 2 = 1.1%; stroke: group 1 = 2.2%, group 2 = 0%; abdominal infarction: group 1 = 3.4%, group 2 = 0%). At follow-up (mean, 15 +/- 12 months) no significant differences were observed in terms of survival free of any cardiac-related event (group 1 = 94.3%, group 2 = 96.5%; p = not significant).
                Off-pump coronary artery surgery could be successfully used for total arterial grafting without compromising the completeness of revascularization. Avoidance of CPB significantly decreased mechanical ventilation support and length of intensive care unit and postoperative stay; however in the absence of risk factors for cardiopulmonary bypass, off-pump coronary artery surgery did not improve early and midterm clinical outcome. The objectives are 2-fold: (1). to serially determine endothelin (ET) levels in arterial vascular compartments in patients undergoing coronary artery bypass surgery using either cardiopulmonary bypass or off-pump techniques, and (2). to define potential relationships between endothelial levels and specific perioperative parameters of patient recovery.
                In a prospective, randomized study, endothelin plasma content was measured from patients undergoing coronary artery bypass grafting using either off-pump techniques (OPCAB group, n = 25) or conventional cardiopulmonary bypass (CPB group, n = 25) before surgery, before and after coronary artery anastomosis, and 6 and 24 hours postoperatively. Specific indices of patient recovery including pulmonary artery pressures, ventilation requirement, and hospital stay were documented for patients in both study groups.
                Postoperative systemic arterial ET levels were significantly increased by 200% in the CPB group and 50% in the OPCAB group. ET levels remained significantly higher in the CPB group relative to the OPCAB group throughout the postoperative period of observation (p < 0.05). Pulmonary artery pressures, ventilation requirement, and hospital stay were significantly increased in patients in the CPB group.
                Postoperative ET levels were higher in patients who underwent CPB for coronary artery bypass surgery. Increased ET in the postoperative period may contribute to a more complex recovery from coronary artery bypass surgery in patients undergoing cardiopulmonary bypass. To evaluate off-pump versus on-pump coronary artery bypass grafting (CABG) in patients with three-vessel disease and a high-risk operative profile.
                A randomised clinical trial.
                Rigshospitalet, University Hospital, Copenhagen, Denmark.
                341 patients with three-vessel disease and a EuroSCORE of 5 or greater. Main exclusion criteria were previous heart surgery, poor left ventricular function (ejection fraction <30%), or unstable preoperative condition.
                CABG performed with versus without cardiopulmonary bypass.
                The primary outcome was a composite of major adverse cardiac and cerebrovascular events (MACCE) including all-cause mortality, acute myocardial infarction, cardiac arrest with successful resuscitation, low cardiac output syndrome/cardiogenic shock, stroke and coronary reintervention.
                MACCE occurred in 69 (40%) patients allocated to off-pump versus 54 (33%) patients allocated to on-pump CABG during the median 3.7 years of follow-up (HR 1.22; 95% CI 0.86 to 1.75; p=0.26). All-cause mortality was significantly increased in the off-pump group (24% vs 15%; HR 1.66, 95% CI 1.02 to 2.73; p=0.04), but cardiac-related death was not significantly different (10% vs 7%; HR 1.30, 95% CI 0.64 to 2.66; p=0.47). An insignificant trend towards a reduction in myocardial infarction after off-pump CABG was observed (7% vs 14%; HR 0.53, 95% CI: 0.27 to 1.04; p=0.06).
                No significant difference in the primary outcome of MACCE was found between off-pump and on-pump CABG. However, mortality seemed higher after off-pump CABG.
                http://clinicaltrials.gov/number, NCT00120991. Off-pump coronary artery bypass grafting reduces postoperative morbidity and uses fewer resources than conventional surgical intervention with cardiopulmonary bypass. However, only 15% to 20% of coronary artery bypass grafting operations use off-pump coronary artery bypass. One reason for not using off-pump coronary artery bypass might be the surgeon's concern about the long-term patency of grafts performed with this technique. Therefore our objective was to compare long-term outcomes in patients randomized to off-pump coronary artery bypass or coronary artery bypass grafting with cardiopulmonary bypass.
                Participants in 2 randomized trials comparing off-pump coronary artery bypass and coronary artery bypass grafting with cardiopulmonary bypass were followed up for 6 to 8 years after surgical intervention to assess graft patency, major adverse cardiac-related events, and health-related quality of life. Patency was assessed by using multidetector computed tomographic coronary angiographic analysis with a 16-slice scanner. Two blinded observers classified proximal, body, and distal segments of each graft as occluded or not. Major adverse cardiac-related events and health-related quality of life were obtained from questionnaires given to participants and family practitioners.
                Patency was studied in 199 and health-related quality of life was studied in 299 of 349 survivors. There was no evidence of attrition bias. The likelihood of graft occlusion was no different between off-pump coronary artery bypass (10.6%) and coronary artery bypass grafting with cardiopulmonary bypass (11.0%) groups (odds ratio, 1.00; 95% confidence interval, 0.55-1.81; P > .99). Graft occlusion was more likely at the distal than the proximal anastomosis (odds ratio, 1.11; 95% confidence interval, 1.02-1.20). There were also no differences between the off-pump coronary artery bypass and coronary artery bypass grafting with cardiopulmonary bypass groups in the hazard of death (hazard ratio, 1.24; 95% confidence interval, 0.72-2.15) or major adverse cardiac-related events or death (hazard ratio, 0.84; 95% confidence interval, 0.58-1.24), or mean health-related quality of life across a range of domains and instruments.
                Long-term health outcomes with off-pump coronary artery bypass are similar to those with coronary artery bypass grafting with cardiopulmonary bypass when both operations are performed by experienced surgeons. The effect of the use of coronary-artery bypass surgery without cardiopulmonary bypass and cardiac arrest ("off pump") on graft patency remains uncertain. We undertook a prospective, randomized, controlled study to compare graft-patency rates and clinical outcomes in off-pump surgery with conventional, "on-pump" surgery.
                We randomly assigned 50 patients to undergo on-pump coronary-artery bypass grafting and 54 to undergo off-pump surgery. Surgical and anesthetic techniques were standardized for both groups. Clinical outcomes and troponin T levels were measured. Three months later, the patients underwent coronary angiography, including quantitative analysis.
                The mean age of the patients was 63 years, and 87 percent were men. The on-pump group received a mean of 3.4 grafts, and the off-pump group 3.1 (P=0.41). There were no deaths. There was no significant difference in the median postoperative length of stay between the two groups (seven days in each group). The area under the curve of troponin T levels was higher during the first 72 hours in the on-pump group than in the off-pump group (30.96 hr x microg per liter vs. 19.33 hr x microg per liter, P=0.02). At three months, 127 of 130 grafts were patent in the on-pump group (98 percent), as compared with 114 of 130 in the off-pump group (88 percent, P=0.002). The patency rate was higher for all graft territories in the on-pump group than in the off-pump group.
                In this randomized study, off-pump coronary surgery was as safe as on-pump surgery and caused less myocardial damage. However, the graft-patency rate was lower at three months in the off-pump group than in the on-pump group, and this difference has implications with respect to the long-term outcome.
                Copyright 2004 Massachusetts Medical Society To assess neurocognitive impairment after the off-pump and on-pump techniques for coronary artery bypass graft surgery in patients with triple vessel disease.
                Randomised controlled trial.
                University Hospital of Wales, Cardiff. Participants: 60 patients undergoing coronary artery bypass graft surgery for triple vessel disease prospectively randomised to the off-pump or on-pump technique.
                Change in scores in nine standard neuropsychometric tests administered preoperatively and at 1 and 10 weeks postoperatively.
                The on-pump group showed a significantly greater deterioration in scores for two and three tests at 1 week and 10 weeks postoperatively, respectively, than the off-pump group. The on-pump group also showed a significantly higher incidence of major deterioration in one of the tests both 1 week and 10 weeks postoperatively. The incidence of neurocognitive impairment at 1 week postoperatively was 27% (8 out of 30) in the off-pump group and 63% (19 out of 30) in the on-pump group (P=0.004); and at 10 weeks postoperatively was 10% (3 out of 30) in the off-pump group and 40% (12 out of 30) in the on-pump group (P=0.017).
                Off-pump coronary artery bypass graft surgery results in less neurocognitive impairment than the on-pump technique. The subset of patients most likely to benefit from off-pump coronary artery bypass grafting (CABG) remains a controversial issue, but the technique has been proposed to decrease postoperative mortality and morbidity. Th e objective of this study was to compare off-pump to onpump CABG in patients with known risk factors for mortality and morbidity.
                Between October 2001 and September 2002, 65 high-risk patients were prospectively randomized to undergo off-pump or o n-pump CABG. Recruited patients had at least 3 of the following criteria: age greater than 65 years, high blood pressure, diabetes, serum creatinine greater than 133 mol/L, left ventricular ejection fraction lower than 45%, chronic pulmonary diseas e, unstable angina, congestive heart failure, repeat CABG, anemia, and carotid atherosclerosis. Hospital mortality and morbidity were the primary end-points of the study.
                Six patients (9%) crossed over from the original randomized group. Twenty-eight patients averaging 70 +/- 8 years of age underwent 3 +/- 1 grafts off pump, and 37 patients averaging 70 +/- 6 years of age underwent 3.4 +/- 1 grafts on pump. Revascularization was considered complete in 21 (7 5 %) of off-pump patients compared to 33 (89%) of onpump patients (P =.1). There were no hospital deaths in off-pump patients, and 2 patients (5%) undergoing onpump CABG died early following surgery (P =.2). Two offpump (7%) compared to 11 on-pump (30%) of patients presented composite end-points including death, neurological injury, renal failure, respiratory failure, and operative myocardial infarction after CABG (P =.02).
                The present study suggests that off-pump CABG, when technically feasible, significantly reduces morbidity following surgery in a group of high-risk patients. This study investigated whether off-pump coronary bypass graft operations on the beating heart under normothermic conditions reduces the systemic oxidative stress and inflammatory reaction seen in patients operated under cardiopulmonary bypass (CPB).
                A cardiac stabilizer (Octopus Tissue Stabilizer; Medtronic Inc, Minneapolis, MN) was used to perform the coronary anastomoses on the normothermic beating heart with or without CPB. Serial blood samples were taken at various intervals. Plasma was analyzed for several oxidative stress and inflammatory markers.
                Significant increases from prior anesthesia values of lipid hydroperoxides (190% at 4 hours), protein carbonyls (250% at 0.5 hours) and nitrotyrosine (510% at 0.5 hours) were seen in the CPB group, but they were abolished or significantly reduced in the off-pump group. Complement C3a and elastase levels were rapidly increased upon the institution of CPB, and this was followed by increases in IL-8, TNF-alpha, and sE-selectin. In contrast, the rise of these factors was blunted in patients operated without CPB.
                Off-pump coronary bypass graft operation on a beating heart significantly reduces oxidative stress and suppresses the inflammatory reaction associated with the use of CPB. The aim of this preliminary, prospective, randomized study was to compare rotation thromboelastography (roTEG) results and D-dimer levels in off-pump versus on-pump coronary surgery in order to identify the activation of fibrinolysis. Twenty patients scheduled for coronary bypass grafting were assessed (off-pump group A, n = 10; on-pump group B, n = 10). Blood samples for roTEG examination were taken preoperatively (t0), 15 minutes after sternotomy (t1), on the completion of peripheral bypass anastomoses (t2), and at the end of procedures (t3). The time points for D-dimer levels analyses were before operation, at the end of procedures, and 24 hours later. A certain degree of roTEG signs of fibrinolysis was noticed at time t2 in both groups and in group B these marks were quite widely, but not significantly expressed (P for intergroup differences for Lysis on Set Time at 60 and 150 minutes were P = 0.190 and P = 0.122, respectively), borderline differences were found for Maximum Clot Firmness (P = 0.082) with a lower mean value for group B (arithmetic means [95% confidence intervals]--57.7 [54.2; 61.2] mm). Completely expressed roTEG signs of hyperfibrinolysis were observed in 2 patients from group B. In group B also the highest geometric means of D-dimers (1326.0 [943.5; 1863.6] ng mL(-1)) and thus a dramatic intergroup difference (P < 0.001) were observed at the end of surgery; 24 hours later the significantly elevated D-dimer levels in both groups (A: 1070.0 [723.5; 1582.6] versus B: 1093.3 [732.0; 1632.9] ng mL(-1)) were equalized (P = 0.932). Our roTEG results display a slightly greater, but fairly subtle activation of fibrinolysis during the course of cardiopulmonary bypass, compared to off-pump cardiac surgery. Cardiopulmonary bypass (CPB) is widely regarded as an important contributor to renal failure, a well recognized complication following coronary artery surgery (coronary artery bypass grafting (CABG)). Anecdotally off-pump coronary surgery (OPCAB) is considered renoprotective. We examine the extent of renal glomerular and tubular injury in low-risk patients undergoing either OPCAB or on-pump coronary artery bypass (ONCAB).
                Forty low-risk patients with normal preoperative cardiac and renal functions awaiting elective CABG were prospectively randomized into those undergoing OPCAB (n=20) and ONCAB (n=20). Glomerular and tubular injury were measured respectively by urinary excretion of microalbumin and retinol binding protein (RBP) indexed to creatinine (Cr). Daily measurements were taken from admission to postoperative day 5. Fluid balance, serum Cr and blood urea were also monitored.
                No mortality or renal complication were observed. Both groups had similar demographic makeup, Parsonnet score, functional status and extent of coronary revascularization (2.1+/-1.0 vs. 2.5+/-0.7 grafts; P=0.08). Serum Cr and blood urea remained normal in both groups throughout the study. A significant and similar rise in urinary RBP:Cr occurred in both groups peaking on day 1 (3183+/-2534 vs. 4035+/-4079; P=0.43) before reapproximating baseline levels. These trends were also observed with urinary microalbumin:Cr (5.05+/-2.66 vs. 6.77+/-5.76; P=0.22). Group B patients had a significantly more negative fluid balance on postoperative day 2 (-183+/-1118 vs. 637+/-847 ml; P=0.03).
                Although renal complication or serum markers of kidney dysfunction were absent, sensitive indicators revealed significant and similar injury to renal tubules and glomeruli following either OPCAB or ONCAB. These results suggest that avoidance of CPB does not offer additional renoprotection to patients at low risk of perioperative renal insult during CABG. The aim of this randomised, prospective study was to evaluate hospital mortality and morbidity after myocardial revascularisation, comparing on-pump coronary artery bypass graft (CABG) myocardial revascularisation versus off-pump coronary artery bypass graft (OPCAB) myocardial revascularisation in population with multivessels coronary artery disease. Sixty patients with multivessels coronary artery diseases were scheduled to undergo coronary artery bypass grafting from January 15, 2006 to June 30, 2007 in our institution. Patients were randomized to off-pump or on-pump surgery with intermittent cross-clamping of aorta and ventricular fibrillation, using the envelope method with random numbers. In the results only difference we did find postoperatively was in Creatine Kinase-MB (CK-MB) release, the amount of bleeding and intensive care unit (ICU) stay (p<0.05). There was no diference between the two groups of patients regarding incidence of main morbidity and hospital moratlity. In summary, we didn't find no superiority in any of the two techniques regarding on hospital mortality and morbidity. Leukocyte activation is thought to be responsible for the adverse effects and postoperative complications following cardiopulmonary bypass (CPB). A novel cell surface molecule, CD97, is a sensitive marker of leukocyte and primary lymphocyte activation. The present study aimed to determine the activation of different leukocyte subsets by comparing the expression of CD97 and adhesion molecules (CD11, CD18) in patients receiving coronary surgery with or without CPB.
                30 patients were enrolled and scheduled for coronary bypass surgery under CPB (20 patients, group A) and with off-pump (OP) operation (10 patients, group B). Blood samples were taken before and during surgery, and over the following first week.
                Here, we report an early decrease in CD97 expression of granulocytes (PMN) and monocytes (MC) followed by an intensive increase reaching the maximum on postoperative days 2 and 3 in patients operated with CPB. The rate of active CD97-positive lymphocytes showed a marked, gradual increase until postoperative day 3 and remained elevated up to day 7 after CPB. OP surgery resulted in moderate alteration in the presence of CD97 on PMN, MC and lymphocytes. The expression of adhesion molecules was similar to CD97 in all leukocyte subsets.
                The findings about CD97 expression suggest considerable leukocyte activation following coronary bypass with CPB compared to OP surgery. The collected data show that the lymphocytes are highly activated and involved in leukocyte sequestration after CPB. Moreover, the importance of CD97 in CPB-related inflammatory response can be stated.
                Copyright (c) 2005 S. Karger AG, Basel. It is well known that conventional coronary revascularization is associated with a pronounced systemic inflammatory response due to the application of cardiopulmonary bypass (CPB).
                To compare the effects of coronary artery bypass grafting (CABG) with (on-pump) or without (off-pump) extra-corporeal circulation observing certain inflammatory response parameters.
                TWENTY PATIENTS UNDERGOING CABG WITH (CPB GROUP: 10 patients) or without (off-pump coronary artery bypass grafting [OPCAB] group: 10 patients) CPB were enrolled in this prospective, randomized study. Blood samples were collected three times during the operation and on postoperative days 1, 2, 3 and 7. The plasma level of proinflammatory cytokine tumor necrosis factor (TNF)-alpha was measured by enzyme-linked immunosorbent assay method following stimulation, and the expression of adhesion molecules (CD11, CD18) of leukocytes were determined by flow cytometry. Furthermore, white blood cell (WBC) and neutrophil count were carried out.
                The WBC and neutrophil counts rose markedly in both groups following the operation and remained at this increased level during the observation period. There was a significant difference in WBC and neutrophil counts between the two groups of patients on postoperative day 7. A significant difference in the level of TNF-alpha was found between the two groups on postoperative day 2 (P<0.05). An intense increase was observed with CPB, which significantly exceeded the values of the OPCAB group without extracorporeal circulation in the early postoperative period. The CD11a and CD18 expression of leukocytes decreased during the operation and on postoperative day 1; thereafter, it increased markedly. There was a significant difference in adhesion molecule expression between the two groups on postoperative day 2.
                The investigation revealed that inflammatory response reactions following extracorporeal circulation could be reduced significantly using the off-pump technique. Pentraxin 3 (PTX3) is a newly identified acute phase reactant with non-redundant functions in innate immunity. The purpose of this study was to assess the kinetics of release of PTX3 in cardiac surgical patients, operated on either with or without the use of cardiopulmonary bypass (CPB).
                Thirty-four patients, seventeen in each group, were randomly assigned to CABG surgery performed either with ("on-pump") or without ("off-pump") CPB. Blood samples were collected both during and after the operation up to the 7(th) day.
                In patients operated on with the use of CPB, PTX3 levels increased throughout the operation. Compared to baseline levels the highest PTX3 value (p<0.000) was attained on the 1(st) postoperative day in both "on-pump" and "off-pump" patients. In contrast to CPB patients, however, PTX3 levels in the latter group declined slowly, remaining elevated as long as the 3(rd) postoperative day (p<0.042).
                Operations performed with the use of CPB are associated with a more pronounced release of PTX3 immediately after operation. Oxidative stress occurs in patients undergoing coronary artery bypass operation. The aim of this study was to investigate the difference in oxidative stress in off-pump versus on-pump coronary artery bypass surgery. In the present study, in serial blood samples, plasma malondialdehyde (MDA) as index of lipid peroxidation, red blood cells glutathione peroxidase (GPx) and superoxide dismutase (SOD) were measured to compare the extent of oxidative stress in 30 patients undergoing OPCAB (off-pump coronary artery bypass grafting), 12 patients undergoing CABG (on-pump coronary artery bypass grafting) and 18 healthy controls. In CABG group, MDA levels increased significantly from 2.87 +/- 0.62 nmol/mL before anesthesia and 2.87 +/- 0.65 nmol/mL after anesthesia to 3.05 +/- 0.66 nmol/mL after ischemia (p < 0.05). Similarly, SOD levels also elevated significantly from 661.58 +/- 78.70 U/g Hb before anesthesia and 659.42 +/- 81.21 U/g Hb anesthesia induction to 678.08 +/- 75.80 U/g Hb after ischemia (p < 0.01, p < 0.01, respectively). In OPCAB group, only SOD levels increased from 581.73 +/- 86.24 U/g Hb anesthesia induction to 590.90 +/- 88.90 U/g Hb after reperfusion (p < 0.05). Glutathione peroxidase levels were not changed according to blood collection times in both of CABG group or OPCAB group (p > 0.05). Our results show that only mild signs of oxidative stress is found after reperfusion in OPCAB operation compared with CABG operation. Further studies are needed in order to confirm this hypothesis. Both cardiopulmonary bypass (CPB) and operative trauma are associated with increased expression of proinflammatory cytokines. We assessed the relative contribution of CPB on activation of various proinflammatory cytokines in patients undergoing coronary revascularization by comparing them with patients receiving coronary artery bypass grafts using off-pump (OPCAB) techniques.
                Twenty-six patients were assigned to either the OPCAB procedure using a suction device and regular sternotomy (n = 13) or were treated conventionally using extracorporeal circulation, blood cardioplegia and hypothermic arrest (29-31 degrees C; n = 13). C-reactive protein and systemic levels of TNF-alpha, TNF specific receptors Rp1 and Rp2, Interleukin-6 (IL-6) and soluble IL-2 receptors (sIL-2r) were assayed by ELISA or EIA. To account for systemic nitric oxide production, total nitrate/nitrite (NOx) was measured using the Griess reaction.
                Coronary revascularization with CPB was associated with a significant expression increase in the TNF-system and sIL-2r when compared to the OPCAB patients. Although IL-6 expression did not differ between both groups, C-reactive protein levels were significantly lower in the OPCAB group. Moreover, systemic NOx levels as the stable end-product of nitric oxide were lower in the OPCAB group.
                The data of the present study indicate that, despite comparable surgical trauma, the OPCAB revascularization procedure without the use of CPB and cardioplegic arrest significantly reduces the systemic inflammatory response syndrome and early catecholamine requirement. This may contribute to improved organ function, subsequently resulting in improved postoperative recovery from surgical revascularization procedures, particularly in critically ill patients. Cardiac operations using extracorporeal circulation bear a risk of cerebral complications. The aim of our study was to investigate if off-pump operations without heart-lung machines can reduce cerebral injury.
                S100, a protein specific for cerebral tissue, was used as a marker for cerebral impairment in 108 randomized patients undergoing coronary bypass operation: 67 patients (group A) were operated on with extracorporeal circulation and cardioplegic cardiac arrest, and 41 patients (group B) underwent off-pump beating heart revascularization. Both groups were similar regarding age, sex, ejection fraction, and number of anastomoses. S100 levels were measured from induction of anesthesia until 24 hours after the operation.
                Data collection was 100% complete. There was no in-hospital death. Nonfatal myocardial infarctions occurred in 2 patients in group A, and 1 patient in group B required resternotomy for bleeding. There was no neurologic deficit in either group. S100 levels increased only slightly in the off-pump patients (group B), whereas in group A there was a sharp rise in S100 concentration during extracorporeal circulation, only returning to baseline 6 hours after the end of the operation. Peak S100 levels were four times higher in group A than in group B (2.1 microg/L versus 0.5 microg/L; p < 001).
                The results of our study suggest that perioperative cerebral impairment is reduced in cardiac operations without the use of extracorporeal circulation. Further large-scale studies are needed to show whether this result is reflected by fewer neurologic deficits. Pulmonary dysfunction is still a major problem in coronary artery bypass grafting (CABG). The purpose of this randomized study was to determine the effect of different CABG techniques on pulmonary function.
                Fifty eight patients with severe obstructive pulmonary disease had elective isolated coronary surgery. The surgical methods for the patients with chronic obstructive pulmonary disease (COPD) were standard CABG in 18 patients (group 1), beating heart surgery in 19 patients (group 2), and minimally invasive direct coronary artery bypass grafting (MIDCABG) in 21 patients (group 3).
                The earliest extubation time was from group 3 (p < 0.001). The average stay in the intensive care unit was significantly longer in group 1 (2.6 +/- 1.5 days) than in groups 2 (1.4 +/- 0.8 days) and 3 (1.1 +/- 0.8 days) (p < 0.05). The most prevalent respiratory morbidity was atelectasis that developed in 6 patients from group 1, in 2 patients from group 2, and in 3 patients from group 3. Forced expiratory volumes in 1 second (FEV1) obtained in the second postoperative month were significantly lower than preoperative values only in group 1 (p < 0.05). Forced vital capacity (FVC) values were significantly lower than the preoperative values in all three groups (p < 0.05).
                Off-pump bypass surgical procedures are more advantageous than on-pump methods for patients with COPD. These patients can be operated on using the beating heart technique or by using MIDCABG to prevent side effects of CPB on pulmonary function and effects of sternotomy. Right ventricular assist devices (RVADs) have been proposed to improve exposure of the coronary arteries in off-pump surgery. In this study we investigated the impact of the A-Med RVAD on inflammatory response and organ function in patients undergoing coronary artery bypass grafting.
                Sixty patients were prospectively randomized to conventional surgery with cardiopulmonary bypass (CPB) and cardioplegic arrest, beating heart surgery (off-pump), or beating heart surgery with the RVAD. Serial blood samples were collected postoperatively, for analysis of inflammatory markers, troponin I, protein S100, and free hemoglobin. Renal tubular function was assessed by measuring urine N-acetyl-glucosaminidase activity.
                No hospital deaths or major postoperative complications occurred in the study population. Interleukin-6, interleukin-8, C3a, and troponin I levels after surgery were significantly higher in the CPB group compared with the off-pump and RVAD groups. Free hemoglobin levels immediately after the operation, peak and total S100 levels, and N-acetyl-glucosaminidase activity were also significantly higher in the CPB group.
                Off-pump coronary revascularization, with or without RVAD, reduces inflammatory response, myocardial, neurologic, and renal injury, and decreases hemolysis when compared with conventional surgery with CPB and cardioplegic arrest. Conventional cardioplegic arrest coronary artery bypass grafting after ST-segment elevation myocardial infarction is associated with high mortality and morbidity. The benefits of off-pump surgery have been suggested. This study randomly evaluated the impact of the off-pump technique on clinical results.
                Between February 2002 and October 2007, 128 patients with ST-segment elevation myocardial infarction who underwent myocardial revascularization within 48 hours from the onset of symptoms were randomly assigned to 2 groups: on-pump group (66 patients/51.5%) and off-pump group (63 patients/48.5%). The primary end point was the incidence of in-hospital death and outcomes (low cardiac output syndrome, prolonged mechanical and pharmacologic cardiac support, prolonged mechanical ventilation support, and postoperative length of stay in intensive care unit and hospital). The secondary end point was the evaluation of myocardial infarct size measured by the perioperative serum release of cardiac troponin I and the improvement of contractile cardiac function evaluated by the wall motion score index.
                Overall in-hospital mortality was 4.6%. In-hospital mortality was 7.7% (5 patients) in the on-pump group and 1.6% (1 patient) in the off-pump group (P = .04). Statistically significant differences were found between the 2 groups concerning the incidence of low cardiac output syndrome (P = .001), time of inotrope drugs support (P = .001), time of mechanical ventilation (P = .006), reoperation for bleeding (P = .04), intensive care unit stay (P = .01), and in-hospital stay (P = .02). Statistically significant differences also were found between the 2 groups concerning the incidence of in-hospital death in patients who were admitted to surgery in cardiac shock (P = .0018) and patients who underwent surgery within 6 hours from the onset of symptoms (P = .0026). The procedure in 1 patient (1.6%) in the off-pump group was converted to the on-pump beating heart technique. The serum levels of cardiac troponin I were high in the on-pump group during the first 48 hours after surgery. Myocardial function was better in the off-pump group. There were no cardiac-related late deaths, and patients had no recurrent cardiac events.
                Off-pump surgery reduced early mortality and morbidity in patients with ST-segment elevation myocardial infarction in respect to the conventional procedure. Off-pump surgery showed better results than on-pump surgery in patients who underwent surgery within 6 hours from the onset of symptoms and in patients with cardiogenic shock. This prospective randomized study sought to verify the systemic inflammatory response, inflammatory myocardial damage, and early clinical outcome in coronary surgery with the miniaturized extracorporeal circulation system or on the beating heart.
                Sixty consecutive patients were randomized to miniaturized extracorporeal circulation (n = 30) or off-pump coronary revascularization (off-pump coronary artery bypass grafting, n = 30). Intraoperative and postoperative data were recorded. Plasma levels of interleukin-6 and tumor necrosis factor-alpha were measured from systemic blood intraoperatively, at the end of operation, and 24 and 48 hours thereafter. Levels of the same markers and blood lactate were measured from coronary sinus blood intraoperatively to evaluate myocardial inflammation. Markers of myocardial damage were also analyzed.
                One patient died in the off-pump coronary artery bypass grafting group. There was no statistical difference in early clinical outcome in both groups. Release of interleukin-6 was higher in the off-pump coronary artery bypass grafting group 24 hours after the operation (P = .03), whereas levels of tumor necrosis factor-alpha were not different in both groups. Cardiac release of interleukin-6, tumor necrosis factor-alpha, and blood lactate were not different in both groups. Release of troponin T was not significantly different in both groups. Levels of creatine kinase mass were statistically higher in the miniaturized extracorporeal circulation group than in the off-pump coronary artery bypass grafting group, but only at the end of the operation (P < .0001). Hemoglobin levels were significantly higher in the miniaturized extracorporeal circulation group than in the off-pump coronary artery bypass grafting group after 24 hours (P = .01).
                Miniaturized extracorporeal circulation can be considered similar to off-pump surgery in terms of systemic inflammatory response, myocardial inflammation and damage, and early outcome. Cardiac surgery is followed by various degrees of inflammation, which have harmful consequences. Because of the central role of extracorporeal circulation (EC), off-pump coronary bypass surgery is deemed preferable. Do different modalities of EC challenge this view?
                Four groups of similar patients underwent coronary surgery: (group 1) on-pump, EC with closed surface modifying additives (SMA) circuit and no pump suckers (n = 20); (group 2) on-pump, EC with open SMA circuit and pump suckers (n = 20); (group 3) off-pump (beating heart) and heparin 3 mg/kg (n = 20); (group 4) off-pump (beating heart) and heparin 1 mg/kg (n = 20). Interleukins (IL)-6, IL-8, IL-10, myeloperoxidase, elastase, and terminal complex of the complement (TCC) were analyzed at various times: at induction (time I); after heparin (time II); after complete revascularization (time III); after protamine (time IV); and 24 hours later (time V).
                The TCC was significantly higher in groups 1 and 2 at time III. The pattern of IL-6 was the same for the four groups. No significant difference in myeloperoxydase content was noted; however, elastase was significantly higher in the two EC (on-pump) groups.
                Except for the complement system and elastase, on-pump surgery with SMA-coated circuits did not elicit any greater inflammatory response than off-pump surgery. We sought to investigate the release pattern of different cardiac biomarkers (high-sensitivity C-reactive protein, cardiac troponin I, heart-type fatty acid-binding protein, creatine kinase-MB, and myoglobin) and to establish the diagnostic discrimination limits of each marker protein to evaluate perioperative myocardial injury in patients undergoing coronary artery bypass grafting with or without cardiopulmonary bypass.
                Fifty patients were randomly assigned to on-pump or off-pump coronary artery bypass grafting. All cardiac biomarkers were measured in serial venous blood samples drawn before heparinization in both groups and after aortic unclamping at 1, 2, 4, 8, 24, 48, and 72 hours in the on-pump group. In the off-pump group samples were taken after the last distal anastomosis and at same time intervals as in the on-pump group.
                The total amount of heart-type fatty acid-binding protein, cardiac troponin I, and high-sensitivity C-reactive protein released was significantly higher in the on-pump group than in the off-pump group. Receiver operating characteristic curve analysis of cardiac biomarkers indicated cardiac troponin I and heart-type fatty acid-binding protein as the superior diagnostic discriminators of myocardial injury, with an optimal cutoff value of greater than 0.92 ng/mL (area under the curve, 0.95 [95% CI, 0.88-1.00]; sensitivity, 92%; specificity, 92%; likelihood ratio [+], 11.50) and greater than 6.8 ng/mL (area under the curve, 0.94 [95% CI, 0.88-1.00]; sensitivity, 88%; specificity, 88%; likelihood ratio [+], 7.33), respectively. Logistic regression analysis revealed that patients with increased cardiac troponin I levels of greater than 0.92 ng/mL and heart-type fatty acid-binding protein levels of greater than 6.8 ng/mL were at 132.25 (95% confidence interval, 17.14-1020.49) times and 53.77 (95% confidence interval, 9.76-296.12) times higher risk of myocardial injury after on-pump coronary artery bypass grafting.
                Off-pump coronary artery bypass grafting provides better myocardial protection than on-pump coronary artery bypass grafting. Cardiac troponin I and heart-type fatty acid-binding protein, but not high-sensitivity C-reactive protein, served as superior diagnostic discriminators of perioperative myocardial damage after on-pump coronary artery bypass grafting. Previous randomized comparisons of off-pump and on-pump coronary artery bypass grafting (CABG) have yielded controversial results about the cardiac and neurological events and graft patency. In addition, these randomized studies were composed of CABG with a few arterial grafts. We performed a prospective randomized controlled study to compare off-pump and on-pump CABG with multiple arterial grafts.
                Between July, 2002, and September, 2004, 167 consecutive unselected patients referred for elective primary CABG were randomly assigned to undergo multiple arterial off-pump CABG (n=81) or on-pump CABG (n=86). The clinical outcomes and S-100 protein, neuron-specific enolase, and maximum creatine kinase-MB levels were compared. Early graft patency was examined within 3 weeks after the operation by angiography. The number of grafts performed per patient (3.5+/-1.0 for off-pump CABG and 3.6+/-0.9 for on-pump CABG) and the number of arterial grafts performed per patient (3.3+/-1.0 for off-pump CABG and 3.4+/-0.9 for on-pump CABG) were similar. Completeness of revascularization (completed grafts/planned grafts) was 98% in both procedures. There were no hospital deaths in either group. The operation time was significantly (P<0.001) shorter in the off-pump group than in the on-pump group (267+/-60 minutes versus 307+/-59 minutes). The incidence of perioperative complications was similar. The frequency of no need for transfusion was higher in the off-pump group than in the on-pump group (80% versus 55%, P<0.001). The S-100 protein levels at the admission into the intensive care unit were significantly (P<0.001) lower in the off-pump group than in the on-pump group (0.20+/-0.11 ng/mL versus 0.34+/-0.22 ng/mL). The neuron-specific enolase levels at the intensive care unit admission were significantly (P<0.001) lower in the off-pump group than in the on-pump group (10.4+/-9.0 ng/mL versus 16.9+/-6.9 ng/mL). Maximum creatine kinase-MB levels were significantly (P=0.046) lower in the off-pump group than in the on-pump group (17.1+/-16.7 IU/L versus 21.5+/-10.6 IU/L). The overall early graft patency rate with or without stenosis was the same (98%) in both groups, but the rate without stenosis was slightly worse in the off-pump group (93%) than in the on-pump group (96%) (P=0.093). The stenosis-free patency rate in the right coronary area was significantly (P=0.028) worse in the off-pump CABG group (90%) than in the on-pump group (99%).
                Off-pump CABG with multiple arterial grafts was as safe as the conventional on-pump CABG, with similar completeness of revascularization and early graft patency. In a previous study, we showed that oxygenation was impaired for up to 5 day after conventional coronary artery bypass grafting (CABG). As cardiopulmonary bypass (CPB) may have a detrimental effect on pulmonary function, we hypothesized that coronary revascularization grafting without the use of CPB (OPCAB) would affect post-operative oxygenation and release of inflammatory mediators less compared with CABG.
                Low-risk patients scheduled for elective coronary revascularization were randomly assigned to one of two groups (CABG, n = 17 or OPCAB, n = 18). Two parameters of oxygenation, shunt (%) and ventilation-perfusions mismatch, described as DeltaPO(2) (kPa), were estimated for up to 5 days post-operatively. Systemic release of interleukin (IL)-6, -8 and -10, C-reactive protein (CRP) and neutrophils were measured in peripheral blood samples for up to 3 days post-operatively. The lungs participation in the cytokine response was evaluated from mixed venous blood samples taken within the first 16 h post-operatively.
                OPCAB was followed by a higher shunt (P = 0.047), with no difference (P = 0.47) in the deterioration of DeltaPO(2) between the groups. OPCAB was followed by an attenuated systemic release of IL-8 (P = 0.041) and IL-10 (P = 0.006), while the release of IL-6 (P = 0.94), CRP (P = 0.121) and neutrophils (P = 0.078) did not differ between the groups. Indications of an uptake of cytokines in the lungs were found after OPCAB.
                When comparing OPCAB with CABG, oxygenation was more affected and only part of the systemic inflammatory response was attenuated. Cardiopulmonary bypass (CPB) is associated with gut mucosal hypoxia, which may contribute to gastrointestinal complications. We examined gastric mucosal oxygenation together with whole-body oxygen flux in low-risk patients undergoing coronary artery bypass grafting (CABG) with and without CPB.
                Fifty-four patients undergoing primary CABG by the same surgeon were randomized into either on-pump (ONCAB, n=27) or off-pump (OPCAB, n=27) groups. The ONCAB group underwent mild hypothermic (35 degrees C) pulsatile CPB with arterial line filtration. Each patient underwent perioperative monitoring with continuous tonometry and cardiac output devices. Gastric intramucosal pH (pHi), gastric-arterial carbon dioxide partial pressure difference (CO(2) gap), whole-body oxygen delivery (DO(2)) and consumption (VO(2)) and whole-body oxygen extraction fraction were measured at sequential time-points intraoperatively and up to 6 h postoperatively. Anaesthetic management was standardized.
                Both groups had similar demographic makeup and extent of revascularization (ONCAB 2.6+/-0.9 grafts versus OPCAB 2.5+/-0.8 grafts; P=0.55). The ONCAB group had a mean (+/-SD) CPB time of 62+/-25 min and aortic cross-clamp time of 32+/-11 min. In both groups there was a similar and progressive drop in pHi intraoperatively. Postoperatively, there was a gradual separation between the groups with ONCAB patients showing no further decline in pHi, while further deterioration was observed in the OPCAB group up to 6 h postoperatively. There was a significant difference between the groups over time (P=0.03). There was a corresponding progressive rise in CO(2) gap perioperatively in both groups, with ONCAB patients demonstrating superior preservation of gastric mucosal oxygenation in the early postoperative period. Global oxygen utilization measurements showed superior DO(2) and VO(2) in the OPCAB group throughout the study.
                Despite superior global oxygen flux associated with beating-heart revascularization, gastric mucosal hypoxia occurred to similar extents in both groups with worsening trends for the OPCAB patients postoperatively. The splanchnic pathophysiology during beating-heart revascularization should be further explored. We compared profiles of the numbers of circulating endothelial cells (CEC) and the apoptosis-inducing capacity of serum samples on human endothelial cells (hEC) in on-pump and off-pump coronary artery bypass grafting (CABG) patients.
                Blood samples from 30 patients undergoing CABG (randomly assigned to two groups: 15 patients off-pump and 15 on-pump (cardiopulmonary bypass, CPB)) were collected after induction of anesthesia (preoperatively), at weaning from CPB/end of bypass grafting (0 h), and 1, 6, 12, 24, and 48 h afterwards. CEC were isolated with immunomagnetic anti-CD146-coated Dynabeads, and counted in a Nageotte chamber. The apoptosis-inducing activity of serum samples on hEC was examined by a tissue culture assay system. Apoptotic and normal cells were identified using phase contrast/fluorescence microscopy after DNA dye staining.
                CEC numbers and proportions of apoptotic hEC were significantly elevated during and after surgery in both groups (p<0.01). Compared with the on-pump group, CEC and proportions of apoptotic hEC were significantly lower (p=0.04 and p=0.03, respectively) in patients having CABG performed off-pump. Starting at comparable baseline levels, the mean CEC-number was highest at 6h postoperatively with 81.9 ml(-1) (range, 44-141) for on-pump patients and 63.3 ml(-1) (range, 48-105) for off-pump patients. hEC apoptosis peaked also at T4: 16.5+/-2.8% versus 11.3+/-2.2%. In both groups, CEC numbers and proportions of endothelial apoptosis were still elevated at 48 h after surgery.
                The number of circulating endothelial cells and apoptotic endothelial cell death are markers of endothelial activation and damage during CABG. This study provides evidence that CABG with the use of CPB in comparison to OPCAB surgery is associated with a significantly more pronounced endothelial response in the immediate postoperative period. Uncertainty persists regarding the impact of the off-pump technique on coronary bypass graft patency. The primary objective of this study was to assess coronary artery bypass graft patency in patients randomized to off-pump and on-pump multivessel coronary artery bypass grafting (CABG). Secondary objectives were clinical outcomes and neuropsychological functioning.
                One hundred and fifty patients were randomized to off-pump (n = 75) or on-pump CABG (n = 75). Graft patency was assessed by multidetector computed tomography 5 weeks after surgery. The two groups were similar regarding patients' characteristics and logistic Euroscore (3.6 vs. 3.7%). Mean number of grafts performed was 3.5 ± 0.6 and 3.5 ± 0.6 in off-pump and on-pump, respectively (P = 0.7). Raw graft patency rate was 89.9% in off-pump and 95.0% in on-pump (OR 2.2, 95% CI 1.07-4.44; P = 0.03). Nineteen (27%) off-pump and 9 (13%) on-pump patients had at least one occluded graft (P = 0.04) and the proportion of patent grafts per patient was 0.91 ± 0.2 in off-pump vs. 0.96 ± 0.1 in on-pump (P = 0.06). However, after adjusting by heparin dose, graft patency was not statistically different between groups (OR 0.87, 95% CI 0.25-2.98, P = 0.83). At 30 days, there was no statistically significant difference in major adverse events and neuropsychological functioning between off-pump and on-pump groups. One-year follow-up showed similar functional class and positive treadmill exercise tests.
                Under the conditions this trial was conducted, CABG performed off-pump had lower overall graft patency rate than on-pump, which was not statistically different after controlling for total heparin dose. Thirty-day complications, neuropsychological functioning, and one-year clinical and functional outcomes were not statistically different between the two techniques. In order to evaluate the traumatic effects of median sternotomy and cardiopulmonary bypass (CPB) in conventional and minimally invasive coronary artery bypass grafting, inflammatory response was studied in a prospective randomized trial in patients referred to single-vessel coronary artery bypass grafting.
                Four surgical techniques were compared: group 1, median sternotomy with CPB in ten patients (eight male, two female; aged 59.6+/-11.0 years (mean+/-SD)); group 2, median sternotomy and off-pump in ten patients (seven male, three female; aged 65.1+/-10.0 years); group 3, minithoracotomy with CPB in ten patients (seven male, three female, aged 61.2+/-10.4 years); group 4, minithoracotomy and off-pump in ten patients (nine male, one female, aged 62.9+/-9.8 years). All patients received a left internal mammary artery graft to the left anterior descending artery (LAD). Clinical data, perioperative values of cytokines and cardiac enzymes were monitored.
                There were no major complications. Troponin-T and creatine kinase isoenzyme MB (CK-MB) levels were significantly higher in CPB procedures (P<0.0056; multivariate general linear model). Interleukin-6 (IL-6) levels were significantly higher in minithoracotomy procedures. Interleukin-1 (IL-1) was significantly increased in all patients compared with the preoperative values.
                The use of CPB is combined with higher levels of troponin-T and CK-MB as signs of myocardial damage. Surgical access was identified as a trigger of inflammatory response, as minithoracotomy is related to higher levels of IL-6. IL-1 increased in all procedures and this occurred independently of the surgical access or the use of CPB, which points out a potential relationship between inflammatory response and anesthesia. Neither CPB nor surgical access influenced the clinical outcome in the treatment of coronary artery single-vessel bypass grafting. Increased Troponin I levels and pro-inflammatory cytokines have been reported in most patients undergoing cardiac surgery, ascribed to the type and extent of surgery, reperfusion injury, and the method of myocardial protection. We investigated their levels in patients undergoing on-pump (CCAB) or off-pump (OPCAB) coronary artery bypass surgery and whether these correlated with the extent of myocardial injury. One hundred twenty patients were prospectively randomized to undergo OPCAB (n = 60) or CCAB (n = 60). Hemodynamic and respiratory data, as well as serum CK-MB mass fraction, Troponin I, and interleukin (IL)-6, IL-8, and IL-10 levels, were collected perioperatively. Demographic, hemodynamic, and respiratory parameters were similar between the two groups. Troponin I was significantly lower in the OPCAB than in the CCAB group, either at the end of ischemia, end of surgery, 6-hour and 24-hour postoperatively (4 +/- 3, 5 +/- 3, 7 +/- 5, and 8 +/- 3 microg/L, vs. 19 +/- 18, 27 +/- 19, 28 +/- 13.5, and 33 +/- 8.5 microg/L, respectively, p < 0.05). Serum cytokine levels in the OPCAB patients were lower compared to the CCAB group at the end of surgery (32 +/- 35, 25 +/- 30, and 40 +/- 30 pg/ml for IL-6, IL-8, and IL-10 vs. 230 +/- 30, 140 +/- 70, and 125 +/- 50 pg/ml, respectively, p < 0.05). Plasma IL-6 levels correlated with the Troponin I levels at the end of surgery in both groups (r = 0.45, p = 0.01). Thus, OPCAB surgery is associated with reduced levels of Troponin I and activation of cytokines, compared to those in the CCAB group. High levels of these factors could correlate with myocardial damage during coronary artery bypass surgery. This finding warrants further laboratory and clinical confirmation in the future. Preliminary reports have documented the safety of off-pump coronary artery bypass graft compared with conventional coronary artery bypass graft surgery. Whereas off-pump coronary artery bypass graft surgery may be associated with improvement in some short-term outcomes, longer-term outcomes and influence on neurocognitive function have not been fully assessed. We examined short-term and intermediate-term neurocognitive and index admission morbidity and mortality after coronary artery bypass surgery performed with and without the use of extracorporeal circulation.
                We prospectively randomly assigned 201 patients undergoing nonemergent isolated coronary artery bypass graft surgery to conventional coronary artery bypass graft surgery (n = 102) or off-pump coronary artery bypass graft surgery (n = 99). The primary end points of the study were neurocognitive function assessed using a 19-test neurocognitive battery at baseline, discharge, and 6 months. Neurocognitive deficit was defined as a 20% or greater reduction from baseline in at least 20% of the tests. Secondary end points included index admission mortality, stroke, low-output cardiac failure, return to the operating room for bleeding, and postoperative troponin release. Risk ratios and 95% confidence intervals were calculated based on intention-to-treat analysis.
                There was no difference in neurocognitive deficit at discharge (discharge versus preoperative: risk ratio, 0.83; 95% confidence interval, 0.65 to 1.07) or at 6 months (6 months versus preoperative: risk ratio, 0.94; 95% confidence interval, 0.70 to 1.28). There was no significant difference in mortality or morbidity between the two groups. The off-pump coronary artery bypass graft group had fewer patients with troponin release than the conventional coronary artery bypass graft group.
                Off-pump coronary artery bypass graft surgery did not result in decreased frequency of neurocognitive deficit. Off-pump coronary artery bypass graft surgery was associated with substantially lower levels of troponin release after surgery. Despite the accepted utility of delayed-enhancement MRI in identifying irreversible myocardial injury, no study has yet assessed its role as a viability tool exclusively in the setting of coronary artery bypass surgery (CABG), and no study has repeated delayed-enhancement MRI late after revascularization. In a clinical trial in which patients underwent CABG by either the off-pump or on-pump surgical technique, we hypothesized that (1) preoperative delayed-enhancement MRI would have high diagnostic accuracy in predicting viability and (2) the occurrence of perioperative myocardial necrosis would affect late regional wall motion recovery.
                Fifty-two patients undergoing multivessel CABG were studied by preoperative and early (day 6) and late (6 months) postoperative cine MRI for global and regional functional assessment and delayed-enhancement MRI for assessment of irreversible myocardial injury. Preoperatively, 611 segments (21%) had abnormal regional function, whereas 421 segments (14%) showed evidence of hyperenhancement. At 6 months after revascularization, 57% (343 of 611) of dysfunctional segments improved contraction by at least 1 grade. When all preoperative dysfunctional segments were analyzed, there was a strong correlation between the transmural extent of hyperenhancement and the recovery in regional function at 6 months (P<0.001). Of a total of 96 previously dysfunctional but nonenhancing or minimally hyperenhancing myocardial segments that did not improve regional function at 6 months, 35 (36%) demonstrated new perioperative hyperenhancement in the early postoperative MRI scan.
                Delayed-enhancement MRI is a powerful predictor of myocardial viability after surgery, suggesting an important role for this technique in clinical viability assessment. To study the inflammatory reaction and myocardial metabolism in off-pump and on-pump coronary artery bypass patients.
                Fifty coronary artery bypass patients were randomized to off-pump or on-pump operations. Myocardial biopsies were taken to determine myocardial metabolism and inflammation (glutathione (GSH), superoxide dismutase (SOD) and myeloperoxidase (MP)) and plasma samples for indicators of oxidative stress (conjugated dienes (s-BDC), oxidative products of proteins (s-ox-Prot) and low-density lipoprotein (LDL)-total peroxyl radical trapping antioxidant potential (s-TRAP)).
                s-ox-Prot 10 min was 2.11 +/- 0.75 vs 2.69 +/- 0.60 (p = 0.014), s-TRAP 5 min was 861 +/- 180 vs 969 +/- 192 (p = 0.032) and s-TRAP 10 min 857 +/- 176 vs 985 +/- 166 (p = 0.011), GSH 10 min 0.55 +/- 0.19 vs 0.72 +/- 1.16 (p = 0.007) (off-pump vs on-pump). The monobasic (MB) fraction of the creatinine kinase 24 h after the operation was significantly lower in the off-pump group, 20.5 +/- 24.2 vs 61.8 +/- 84.6 (p = 0.023).
                GSH levels from the biopsies were increased in the perfusion group early in the reperfusion time showing that myocardial tissue was well protected and recovered more rapidly after cross-clamping than after the occlusion of the coronary arteries. However, release of creatinine kinase was lower in the off-pump group showing that cardiopulmonary bypass has more deleterious effects later after the operation. The objective of this study was to compare neuropsychologic and quality-of-life outcomes of patients undergoing off-pump coronary artery bypass surgery to those undergoing coronary artery bypass graft surgery using conventional cardiopulmonary bypass.
                A prospective randomized trial of coronary artery bypass graft surgery with and without the use of cardiopulmonary bypass.
                A cardiothoracic surgery unit at a tertiary hospital.
                Sixty-six patients undergoing coronary artery bypass graft surgery and a control group of 50 participants not undergoing cardiac surgery.
                Patients were randomized to receive coronary artery bypass graft surgery with cardiopulmonary bypass or randomized to coronary artery bypass graft surgery without the use of cardiopulmonary bypass.
                The proportions of neuropsychologic deficits and improvement in quality-of-life were comparable regardless of whether patients were randomized to receive off-pump coronary artery bypass graft surgery or conventional coronary artery graft surgery with cardiopulmonary bypass.
                Patients receiving coronary artery bypass grafts without cardiopulmonary bypass did not show fewer cognitive deficits or greater improvement in quality of life. Conventional on-pump coronary artery bypass grafting (CABG) is associated with a systemic inflammatory response and by an increased production of reactive oxygen species, whereas off-pump coronary artery bypass grafting (OPCAB) is thought to be accompanied by less oxidative stress. Urinary isoprostane iPF2alpha-III is a new marker reflecting oxidative stress; it has emerged as the most reliable marker of oxidative stress status in vivo. This study was designed to ascertain whether OPCAB compared with CABG represents a surgical strategy that avoids oxidative stress. To this end urinary isoprostanes and other established oxidative stress markers were measured during the first 24 hours after CABG and OPCAB.
                Fifty low-risk coronary patients were randomly assigned to CABG or OPCAB. Urinary isoprostane iPF2alpha-III levels, plasma levels of free malondialdehyde, and total antioxidant status were measured before, during, and up to 24 hours after surgery.
                In OPCAB iPF2alpha-III excretion remained unchanged throughout the study. As expected, in CABG iPF2alpha-III levels significantly increased during surgery and returned at baseline 24 hours later. Free malondialdehyde behaved similarly, with no change in OPCAB and sharp increases during CABG. Conversely, total antioxidant status showed a sharp drop during CABG, followed by a slow recovery, whereas a significantly lower drop occurred in OPCAB.
                In this randomized study in low-risk coronary patients, OPCAB revealed less perioperative oxidative stress, as reflected by lack of excretion of iPF2alpha-III in urine, by lack of increase of plasma free malondialdehyde, and by lower decreases in plasma total antioxidant status. Acute kidney injury (AKI) is a major postoperative complication following cardiac surgery. Diabetes mellitus is a major cause of nephropathy and end-stage renal failure. We aimed to evaluate the occurrence of adverse renal outcomes, in diabetic patients, between on-pump (CPB) and off-pump (OPCAB) coronary artery bypass graft (CABG). Seventy-one diabetic patients (36 and 35 patients in the CPB and OPCAB groups, respectively) were enrolled in a prospective randomized study. Renal tubular and glomerular functions, were monitored preoperatively and over five consecutive days. There was no significant difference between the groups in terms of age, gender, New York Heart Association class, Canadian Cardiovascular Society functional classification of angina grade and number of CABG. Intensive care unit stay, duration of intubation, hospital stay and bleeding were significantly higher in the CPB group. No significant differences in plasmatic creatinine, urinary creatinine, creatinine clearance, proteinuria or osmolality were detected. A significant rise in urinary albumine excretion occurred in both groups peaking on the operative day; for the on-pump CABG group (10±5 vs. 48±57; P=0.015) and for the OPCAB group (11±6 vs. 37±59; P=0.04). Values were less important in the OPCAB group and return to the baseline was faster than in the CPB group. OPCAB attenuates sub-clinical AKI, in diabetic patients. The activation of the coagulation and fibrinolytic systems and platelet function in patients undergoing coronary artery bypass surgery on-pump or off-pump techniques was compared.
                Thirty-two patients were randomly assigned to on-pump or off-pump coronary artery bypass grafting. Heparin was given at the same dose. Activation of the coagulation and fibrinolytic systems was evaluated by measurement of several markers. Platelet function was evaluated by in vitro bleeding time test. Blood samples were collected at 7 different times, up to postoperative day 6.
                Overall tissue factor production was similar in the two groups. Thrombin formation was more elevated in the on-pump group (P < .001), particularly during the operation; prothrombin fragment 1.2 discharge values were higher than the preoperative ones (P = .002). Levels of tissue-plasminogen activator showed no difference between the groups (P = .1). D-dimers release was higher in the on-pump group (P = .0002). In vitro bleeding time was longer in the on-pump group (P < .0001), particularly in the first 24 hours; it was not prolonged in the off-pump group. In both groups, regardless of aspirin treatment, discharge in vitro bleeding times were lower than the preoperative ones (P < .01).
                Although the extrinsic coagulation pathway is similarly activated, thrombin formation is more pronounced in patients having on-pump bypass grafting. Patients subjected to off-pump bypass grafting have normally functioning platelets and a weak activation of the fibrinolytic system. At discharge, both groups have preserved platelet function and increased thrombin formation. Further studies with angiographic evaluation are needed to establish a correlation between coagulation parameters, platelet function, and graft patency. To compare the clinical, angiographic, neurocognitive, and quality of life outcomes of off-pump coronary artery bypass surgery with conventional coronary artery bypass grafting surgery using cardiopulmonary bypass.
                Randomised controlled clinical trial.
                Tertiary cardiothoracic centre in Middlesex, England.
                168 patients (27 women) requiring primary isolated coronary artery bypass grafting surgery.
                Patients were randomised to conventional coronary artery bypass grafting surgery using cardiopulmonary bypass (n = 84) or off-pump coronary artery bypass surgery (n = 84), carried out by one surgeon. Angiographic examination was carried out at three months postoperatively. Neurocognitive tests were carried out at baseline and at six weeks and six months postoperatively.
                Clinical outcome, graft patency at three months, neurocognitive function at six weeks and six months, and health related quality of life.
                Graft patency was evaluated by angiography in 151 (89.9%) patients and was similar between the cardiopulmonary bypass and off-pump groups (risk difference - 1%, 95% confidence interval - 5% to 4%), with the off-pump group considered the treatment group. Patients in the off-pump group required fewer blood transfusions (1.7 units v 1.0 unit, P = 0.02), shorter duration of mechanical ventilation (7.7 hours v 3.9 hours, P = 0.03), and shorter hospital stay (10.8 days v 8.9 days). Scores for neurocognitive function showed a significant difference in three memory subtests at six weeks and two memory subtests at six months in favour of the off-pump group.
                Patients who underwent off-pump coronary artery bypass surgery showed similar patency of grafts, better clinical outcome, shorter hospital stay, and better neurocognitive function than patients who underwent conventional coronary artery bypass grafting surgery using cardiopulmonary bypass. In order to investigate the neuroprotective efficacy of off-pump coronary artery bypass surgery (OPCAB) over conventional on-pump coronary artery bypass surgery (CCAB), we have performed a prospective randomized study evaluating retinal circulation changes after OPCAB and CCAB.
                Twenty patients were randomized to OPCAB or CCAB. Retinal fluorescein angiography and 60 degrees black-and-white as well as color fundus photographs of both eyes of each patient were taken 1 to 24 h before and 5 to 6 days after the operation.
                Patients undergoing OPCAB had more severely stenosed carotid arteries (P=0.075), higher incidence of slightly diseased ascending aorta (P=0.087) and higher Northern New England Cardiovascular Study Group stroke risk score (P=0.075). Neither stroke nor transient ischemic attack occurred postoperatively in these patients. Inferotemporal retinal arterial embolization and microinfarction was detected in one patient after CCAB, but in none of the OPCAB group.
                The risk of retinal embolism can be minimized by the use of OPCAB and, most likely, by adequate epiaortic ultrasound scanning of the ascending aorta and avoiding clamping in case of severely diseased aorta. Changes in hemostasis after off-pump coronary artery bypass grafting are still being discussed. There is a lack of information about platelet activity and aspirin efficacy after coronary artery bypass grafting. The aim of this study was to assess and compare platelet activity and aspirin efficacy early and late after off-pump and on-pump coronary artery bypass grafting.
                Eighty patients were enrolled in a prospective randomized study. Platelet activity was determined based on membrane expression of antigen CD62P (P-selectin) by means of flow cytometric analysis. Aspirin efficacy was assessed by using arachidonic acid-induced platelet aggregation. Blood samples were collected before the operation, immediately postoperatively, and on days 1, 2, 5, and 30.
                In the off-pump group expression of P-selectin was markedly increased in comparison with preoperative values, with a maximum difference observed on day 2 (+53%, P = .02), and it was significantly higher compared with that seen in the on-pump group on days 2 and 5 (+53% vs +4%, P = .004, and +20% vs -16%, P = .005). On day 30, P-selectin expression was similar both between the groups and in comparison with the preoperative values. Arachidonic acid-induced platelet aggregation was gradually decreasing until day 30, but on day 2, there was an unexpected increase in aggregation that was more expressed in the off-pump group.
                The platelet activity is higher in the early postoperative period in off-pump compared with on-pump coronary artery bypass grafting. The present aspirin strategy seems to be insufficient in the early postoperative period, irrespective of the surgical technique used. Postoperative atrial fibrillation is common after coronary surgery. The cellular condition of atrial myocytes might play a part in the postoperative development of atrial fibrillation. Our study aimed to investigate whether patients in whom postoperative atrial fibrillation develops show pre-existent alterations in histopathology of the right atrium and how such changes are expressed in relation to the use of cardiopulmonary bypass.
                Seventy patients undergoing elective coronary revascularization were prospectively randomized to on-pump conventional surgery (conventional coronary artery bypass grafting, n = 35) or off-pump surgery on the beating heart (off-pump coronary artery bypass grafting, n = 35). Samples from the right atrial appendage were immediately collected after opening the pericardium. In the on-pump group samples were also taken after weaning from cardiopulmonary bypass. Focusing on degenerative alterations, histology was studied by means of light microscopy and for confirmation of particular findings by means of electronic microscopy.
                Twenty-two (31%) patients had postoperative atrial fibrillation, with the rate not being different between the off-pump coronary artery bypass grafting and conventional coronary artery bypass grafting groups (P = .797). Left atrial enlargement and inotropic requirement were related to atrial fibrillation. Interstitial fibrosis, vacuolization, and nuclear derangement of myocytes were the histologic abnormalities associated with the development of postoperative atrial fibrillation. However, in multivariate analysis fibrosis was confounded by myocyte vacuolization (P = .002) and nuclear derangement (P = .016), representing independent atrial fibrillation predictors. As expected, the conventional coronary artery bypass grafting and off-pump coronary artery bypass grafting groups showed similar histology, but more importantly, no atrial changes were detected in relation to cardiopulmonary bypass exposure in the conventional coronary artery bypass grafting group. Atrial histology showed degenerative changes that correlated with advanced age and left atrial enlargement.
                Our study supports the contention that atrial fibrillation after coronary surgery is associated with pre-existing histopathologic changes of the right atrium. Patients randomly allocated to off-pump coronary artery bypass grafting procedures showed a similar rate of atrial fibrillation and a similar relationship to atrial histology as did those exposed to cardiopulmonary bypass. Cardiopulmonary bypass did not cause additional changes in tested histology variables. Right ventricular dysfunction is a possible cause of cardiac failure after coronary surgery. The use of cardiopulmonary bypass is regarded as a major cause for its occurrence, and it has been postulated that performing coronary surgery without cardiopulmonary bypass might reduce ventricular dysfunction. Therefore, this prospective, randomized, controlled study tested the hypothesis that off-pump coronary surgery would better preserve right ventricular systolic and diastolic function than conventional bypass surgery.
                Fifty patients scheduled for elective coronary artery bypass surgery were randomly assigned to conventional or off-pump surgery. Right ventricular function was assessed by intraoperative transesophageal echocardiography immediately before and after coronary surgery. Right ventricular ejection fraction was used as a marker of global systolic function and tricuspid early/late (atrial) ratio as a marker of the global diastolic function. Peak systolic and early diastolic velocities of the lateral tricuspid annulus were studied to assess systolic and diastolic function in the area of the right ventricular free wall.
                Surgery was completed according to randomization in 48 of 50 patients. Preoperative characteristics were similar in both groups. Intraoperative differences between the two groups included a higher volume of allogeneic blood transfusion in the conventional surgery group. At the end of surgery, global systolic right ventricular function was similarly maintained and diastolic function similarly impaired in both groups. There were no significant intergroup differences in any of the echocardiographic markers of right ventricular function.
                Off-pump surgery did not better preserve right ventricular systolic and diastolic function than did conventional coronary surgery. The feasibility of complete revascularization on the beating heart without cardiopulmonary bypass (CPB) as compared with the standard operation with CPB in elective low-risk patients with multivessel disease has not been clearly demonstrated in a prospective trial.
                Eighty selected low-risk patients were enrolled. In preoperative study with coronary angiography, the decision was made whether complete revascularization without CPB could be performed. Patients were randomly assigned to receive CABG either with (n = 40) or without CPB (n = 40). Randomization criteria were age, sex, and left ventricular ejection fraction. Completeness of revascularization as well as short- and mid-term clinical outcome in a 13.4 +/- 6.5 month follow-up period were monitored.
                Twenty-six of 40 (65%) patients undergoing CABG without CPB underwent complete revascularization. In 5 of these patients (12.5%) suitable vessels were discarded for technical reasons and 9 patients (22.5%) were switched to CABG with CPB owing to the deeply intramyocardial course of target vessels (n = 5) or to hemodynamic instability (n = 4). In the group of patients operated on with CPB, 34 of 40 patients (85%) received complete revascularization. In 6 patients (15%) suitable vessels were discarded for technical reasons. Mean number of bypass grafts was 3.1 +/- 0.8 with CPB and 2.6 +/- 0.5 without CPB (p = 0.043). Clinical outcome and hospital stay were comparable in both groups. No patient died during the study period. No myocardial infarction was observed. Three patients undergoing CABG without CPB underwent successful PTCA 3 months after surgery.
                CABG without the use of CPB is effective for complete revascularization in the majority of selected low-risk patients. Nevertheless, it has to be stated that the rate of incomplete revascularization in this early series of CABG without CPB is higher, and compromises the basic principle of complete revascularization. In coronary artery bypass grafting (CABG) without cardiopulmonary bypass (CPB) the inflammatory response is suggested to be minimized. Coronary anastomoses are performed during temporary coronary occlusion. Inflammatory response and myocardial ischaemia need to be studied in a randomized study comparing CABG in multivessel disease with versus without CPB.
                Following randomization 30 consecutive patients received CABG either with (n=16) or without CPB (n=14). Primary study endpoints were parameters of the inflammatory response (interleukin (IL)-6, interleukin-10, ICAM-1, P-selectin) and of myocardial injury (myoglobin, creatine kinase-MB (CK-MB), troponin I) (intraoperatively, 4, 8, 16, 24 and 48 h after surgery). The secondary endpoint was clinical outcome.
                The incidence of major (death: CABG with CPB n=1, not significant (n.s.)) and minor adverse events (wound infection: with CPB n=2, without CPB n=1, n.s. ; atrial fibrillation: with CPB n=3, without CPB n=2, n.s.) was comparable between both groups. The release of IL-6 was comparable during 8 h of observation (n.s.). Immediately postoperatively IL-10 levels were higher in the operated group with CPB (211.7+/-181.9 ng/ml) than in operated patients without CPB (104.6+/-40.3 ng/ml, P=0.0017). Thereafter no differences were found between both groups. A similar pattern of release was observed in serial measures of ICAM-1 and P-selectin, with no difference between both study groups (n.s.). Eight hours postoperatively the cumulative release of myoglobin was lower in operated patients without CPB (1829.7+/-1374. 5 microg/l) than in operated patients with CPB (4469.8+/-4525.7 microg/l, P=0.0152). Troponin I release was 300.7+/-470.5 microg/l (48 h postoperatively) in patients without CPB and 552.9+/-527.8 microg/l (P=0.0213). CK-MB mass release was 323.5+/-221.2 microg/l (24 h postoperatively) in operated patients without CPB and 1030. 4+/-1410.3 microg/l in operated patients with CPB (P=0.0003).
                This prospective randomized study suggests that in low-risk patients the impact of surgical access on inflammatory response may mimic the influence of long cross-clamp and perfusion times on inflammatory response. Our findings indicate that multiregional warm ischaemia, caused by snaring of the diseased coronary artery, causes considerably less myocardial injury than global cold ischaemia induced by cardioplegic cardiac arrest. Adverse effects on the respiratory system can be severe in many instances after coronarv artery bypass grafting (CABG) with cardiopulmonary bypass (CPBP). Recently, operative techniques without CPBP have gained widespread consent, thanks to the newly developed retractors that allow satisfactory immobilisation of the surgical field.
                Thirty-seven patients operated upon in our Institution between April 1997 and April 1998 showed an obstructive and/or restrictive pulmonary disease. Twenty-one patients were operated on without CBPB (group A), while 16 patients were operated using CPBP (group B, control). The allocation in each group had been randomised.
                The length of the operation in group A was less than in group B (196+/-35 minutes vs 235+/-60 minutes), (p=0.014). A significant difference was found in postoperative bleeding: 562+/-381 ml vs 776+/-378 (p=0.046), in postoperative red cell count, hemoglobin level and Hct. Permanence on the ventilator was 19.1+/-13 hours in group B and 13.1+/-6.1 hours in group A (p=0.03). The length of stay in ICU was significantly different: 33.8+/-16.2 hours for group A vs 53.6+/-29.3 hours for group B (p=0.01). No respiratory failure occurred in group A; two patients experienced slow weaning from ventilation assistance and one died from that complication in group B.
                Myocardial revascularization without CPBP allows a better postoperative clinical course in patients with advanced pulmonary disease. Prior studies showed that postoperative increase in plasminogen activator inhibitor-1 (PAI-1) levels is associated with an increased risk of graft occlusion after coronary artery bypass surgery (CABG). This prospective study aimed to compare the changes of PAI-1 antigen levels after off-pump and on-pump CABG. Forty-four patients admitted for elective CABG were randomised to on-pump (n=22) or off-pump (n=22) surgery. Serum samples were collected for estimation of PAI-1 and tissue plasminogen activator (t-PA) antigen levels preoperatively and 2 h after the operation. The groups were similar in terms of age, weight, gender ratio and extent of coronary disease, left ventricular function and number of grafts per patient. Fibrinogen and t-PA levels increased postoperatively in both the groups when compared with baseline values. After operation, statistical analysis revealed that increase of PAI-1 values was higher in off-pump group (44.1+/-9.1 vs. 25.3+/-6.9) than on-pump group (37.2+/-5.5 vs. 27.3+/-7.8, p=0.002). This study shows that increase in PAI-1 antigen values in patients who undergo off-pump (beating heart) CABG is significantly higher than in those who undergo conventional CABG with cardiopulmonary bypass. The aim of the study was to compare energetic metabolism in the myocardium during coronary surgery with and without cardiopulmonary bypass by means of microdialysis.
                Twenty-six low-risk patients were prospectively randomized to off-pump versus on-pump surgery. Microdialysis was used to sample myocardial interstitial fluid during and for 23 hours after surgery.
                Preoperative characteristics and clinical outcome were similar in both groups. Blood glucose and lactate did not differ between groups throughout the observation time. During surgery, intramyocardial levels of glucose, pyruvate and urea were unaffected in off-pump patients, while the same substances significantly decreased (p<0.05) in on-pump patients during cardioplegic arrest, and increased during reperfusion. Interstitial lactate levels were higher during off-pump surgery (p<0.05). From 3 to 15 hours after surgery, intramyocardial concentrations of glucose, urea and lactate were higher in off-pump patients (p<0.001), while pyruvate was higher in on-pump patients (p<0.01). Intramyocardial lactate/pyruvate ratio never differed between groups. Postoperatively, cumulative blood release of troponin-T was significantly higher in the on-pump group (p<0.005).
                Microdialysis could demonstrate significant differences in energetic metabolism between the two groups. Our data confirm and might help in explaining the lower release of myocardial ischemic markers after off-pump surgery.
                Copyright © 2009 Elsevier Ireland Ltd. All rights reserved. Off-pump coronary artery bypass grafting (OPCAB) is associated with a less intense systemic inflammatory response according to biochemical markers. We studied systemic vascular resistance (SVR) as a physiologic response to systemic inflammatory response to determine any differences between OPCAB and on-pump coronary artery bypass grafting (ONCAB) in a prospective randomized trial.
                One hundred consecutive patients were randomized to OPCAB or ONCAB, 50 in each group. Antifibrinolytics and steroids were not used. All protocols were identical except for cardiopulmonary bypass. Temperature, SVR index, cardiac index, and blood pressure were measured continuously for the first 24 hours postoperatively. All patients were reviewed at 30 days.
                There was no 30-day mortality, no stroke, and no acute renal failure. Mean temperature peaked at 37.5 degrees C at 12 hours (p = 0.700 between groups). Mean SVR index fell to 1,900 dyne x cm(-5) x m(-2) at 12 to 18 hours; 42% of OPCAB and 32% of ONCAB patients developed very low SVR index (<1,500 dyne x cm(-5) x m(-2)). The incidence of high SVR (>2,500 dyne x cm(-5) x m(-2)) fell from 20% to 2% by 12 to 18 hours. The extent and pattern of SVR index responses were similar in both groups (p = 0.840). Mean cardiac index peaked at 3.0 L x min(-1) x m(-2), 12 to 18 hours postoperatively (p = 0.815 between groups); 84% of OPCAB and 90% of ONCAB had cardiac index greater than 2.2 L x min(-1) x m(-2) at all times. Only 10% of patients required vasopressors. Blood pressure responses were also similar (p = 0.314).
                The incidence of low SVR, and patterns of SVR changes were similar in ONCAB and OPCAB, and were clinically unimportant as few patients required vasopressor support. Cardiac outputs and clinical outcomes were excellent in both groups. The clinical benefit of off-pump coronary artery bypass graft surgery over on-pump surgery is a matter of controversy. The aim of this study was to assess quality of life in patients after on-pump and off-pump coronary artery bypass graft surgery, and compare the data with an age-matched and sex-matched standard population.
                Two hundred twelve patients admitted for elective coronary artery bypass graft surgery were randomized to on-pump (n = 104) and off-pump (n = 108) surgery. Quality-of-life assessments were made 6 and 18 months postoperatively using the standard form of the Medical Outcomes Study 36-Item Short Form Health Survey (SF-36, version 2). The questionnaire yields eight subscores of functional health and well being. The eight SF-36 raw scores were standardized using means and standard deviations from a random sample of adults in Great Britain. Mean on-pump and off-pump SF-36 scores were compared using two-sample Student's t tests.
                Questionnaires were completed for 72% (154 of 212) and 46% (98 of 212) of patients at the 6- and 18-month follow-up, respectively. There were no significant differences between on-pump and off-pump patients in any of the eight subscales at both stages. Fifty-six (72%) on-pump and 59 (75%) off-pump patients reported a better health status compared with the 6-month period before surgery (not significant).
                Patients who have undergone off-pump coronary artery bypass graft surgery have a similar quality of life to on-pump patients at 6 and 18 months after surgery. For both groups, the majority of patients reported improved health after coronary artery bypass graft surgery compared with their preoperative status. We aimed to evaluate the clinical results and biocompatibility of the minimal extracorporeal circulation system (MECC) compared with off-pump coronary revascularization (OPCABG).
                In a prospective randomized study, 150 patients underwent coronary surgery with the use of MECC and 150 underwent OPCABG. End points were (1) circulating markers of inflammation and organ injury, (2) operative results, and (3) outcome at 1-year follow-up. Operative mortality and morbidity were comparable between the groups. Release of inflammatory markers was similar between groups at all time points (peak interleukin-6 167.2+/-13.5 versus 181+/-6.5 pg/mL, P=0.14, OPCABG versus MECC group, respectively). Peak creatine kinase was 419.3+/-103.5 versus 326+/-84.2 mg/dL (P=0.28), and peak S-100 protein was 0.13+/-0.08 versus 0.29+/-0.1 pg/mL (P=0.058, OPCABG versus MECC group, respectively). Length of hospital stay and use of blood products were similar between groups. Two cases of angina recurrence at 1 year in the MECC group were observed versus 5 cases observed in the OPCABG group (P=0.44). A residual perfusion defect at myocardial nuclear scan was less frequent among patients in the MECC group (3 versus 9 cases, P=0.14; odds ratio 0.32, 95% confidence interval 0.07 to 1.32). Six (OPCABG group) versus 3 (MECC group) coronary grafts were occluded or severely stenotic at 1 year (P=0.33, odds ratio 0.47, 95% confidence interval 0.09 to 2.14).
                Clinical results of coronary revascularization with MECC are optimal when this procedure is performed by experienced teams. Postoperative morbidity is comparable to that with OPCABG. MECC is associated with little pump-related systemic and organ injury. It may achieve the benefits of OPCABG (less morbidity in high-risk patients) while facilitating complete revascularization in the case of complex lesions unsuitable for OPCABG. To evaluate hospital mortality and morbidity after myocardial revascularization in a prospective and multicenter study, comparing on-pump versus off-pump in a special subset of patients with lesions in the left descending artery, alone or associated with the right coronary artery.
                A multicenter prospective randomized study was performed. One hundred and sixty selected low-risk patients were enrolled; 80 patients were operated on-pump (coronary artery bypass grafting [CABG], group I) and 80 patients were operated off-pump (off-pump coronary artery bypass [OPCAB], group II). One hundred and five were male and ages ranged from 39 to 70 years old; mean 58.81 +/- 9.31 and median 59. Preoperative clinical characteristics were similar in both groups; only previous myocardial infarction was higher in the OPCAB group. Patients with severe left ventricular dysfunction (FE </= 35%), renal failure and lesions of the circumflex artery and its branches were excluded, as well as patients with significant comorbidities that were inappropriate for randomization because we selected them for OPCAB procedures.
                Hospital mortality was 2.5%, three patients (3.7%) in group I (on-pump) and one patient (1.2%) in group II (off-pump) (ns). The number of grafts per patients in group I was 1.81 +/- 0.6, and 1.77 +/- 0.68 in group II (p = 0.833). There was no difference in the total operation time 205.10 +/- 54.30 minutes in group I and 189.50 +/- 55.44 in group II (ns). Six patients (7.5%) had myocardial infarction in group I and three (3.7%) in group II (ns). Bleeding in the postoperative period was 680.50 +/- 434.1 mL in the on-pump group and 678.6 +/- 357.0 mL in the off-pump group (ns). Three patients (3.7%) presented transient neurologic dysfunction in group I and six patients (7.5%) in group II (ns). Intensive care stay was 2.4 +/- 1.0 days in the CABG and 2.3 +/- 0.98 days in the OPCAB group (ns).
                We did not find any statistical difference in hospital mortality and morbidity using on-pump or off-pump techniques for low-risk patients. Cardiac surgery initiates a systemic inflammatory response, which may affect endothelial function. The aim of this study was to investigate if off-pump CABG (OPCAB) reduces the postoperative inflammatory response and affects endothelial function less than conventional on-pump CABG.
                Fifty-two patients submitted for elective CABG were included in a prospective, randomized study. Twenty-six patients were operated with, and 26 without cardiopulmonary bypass (CPB). Plasma levels of complement (C3a), cytokines (IL-8, TNF-alpha), endothelin-1 and neopterin were measured before and during surgery and 2 and 24 h after surgery. Endothelial function was assessed by forearm plethysmography and acetylcholine infusion in 30 patients 2-4 h after surgery.
                C3a and neopterin concentrations were significantly higher during and early after surgery in the CPB group while TNF-alpha and IL-8 tended to be higher in the CPB group but the difference did not reach statistical significance. Endothelial function did not differ significantly between the two groups.
                OPCAB reduces complement activation compared with on-pump CABG but does not significantly affect TNF-alpha and IL-8 release or endothelial function. S100 protein has been used as a marker for cerebral injury. Studies have reported lower levels in off-pump coronary artery surgery (CABG) compared to on-pump surgery. However, most of these are flawed as S100 from extracerebral sources was included (e.g. blood from cardiotomy suckers). Microemboli (high-intensity transient signals or HITS) during CABG have been implicated as a cause of postoperative neurocognitive dysfunction. The aim of this study was to compare the number of HITS during on-pump and off-pump CABG, measure S100 accurately by excluding extracerebral sources, and assess whether any changes in S100 were related to HITS.
                Thirty-five patients admitted for CABG were randomised to on-pump (n=20) or off-pump (n=15) surgery. Bilateral transcranial Doppler ultrasonography was performed on the middle cerebral artery to detect HITS. S100 was measured preoperatively, at termination of bypass in on-pump surgery, at completion of anastomoses in off-pump surgery, and 48 h postoperatively. A cell saver was used instead of cardiotomy suction in the on-pump group in order to limit extracerebral contamination of the S100 assay.
                The number of HITS was 2016+/-1897 during on-pump and 16+/-21 during off-pump surgery (P<0.0001). In on-pump surgery S100 increased from 0.05+/-0.03 to 0.50+/-0.28 microg/l (P<0.0001) at termination of bypass. In off-pump surgery S100 increased from 0.08+/-0.05 to 0.35+/-0.20 microg/l (P<0.0001) at completion of anastomoses. The mean intraoperative S100 in the on-pump group was 1.6 times greater compared to that in the off-pump group (95% CI 0.88-2.8; P=0.01). There was no evidence of a relationship between S100 and HITS in both groups. By 48 h S100 decreased to 0.22+/-0.14 microg/l in the on-pump and 0.21+/-0.09 microg/l in the off-pump group (P<0.0001, compared to the preoperative value).
                We have demonstrated a significantly higher number of cerebral microemboli in patients undergoing on-pump compared to off-pump CABG. By limiting contamination from extracerebral sources, we have shown S100 beta levels during on-pump CABG one and a half times greater than that in off-pump, although this did not reach statistical significance. In addition, we have shown no correlation between S100 beta and the total microemboli count, possibly because of the small numbers in this study. The aim of this prospective study was to determine whether the inflammation-associated clinical morbidity as well as the subclinical markers of the inflammatory response are reduced in patients who undergo minimally invasive coronary artery bypass grafting without cardiopulmonary bypass.
                From June 1995 to June 1996, 62 consecutive patients with isolated stenosis of the left anterior descending coronary artery were assigned randomly to two groups: 31 patients underwent minimally invasive coronary artery bypass grafting and 31 patients underwent conventional coronary artery bypass grafting with cardiopulmonary bypass. In a subgroup of 10 patients in each group, subclinical markers were measured to determine the level of the inflammatory response generated during the operation.
                In the group that underwent minimally invasive coronary artery bypass grafting, leukocyte elastase, platelet beta-thromboglobulin, and complement C3a were unchanged at the end of the procedure compared with their baseline concentrations, whereas these inflammatory markers were increased significantly in the group that underwent conventional coronary artery bypass grafting with cardiopulmonary bypass. The patients who underwent minimally invasive coronary artery bypass grafting had a shorter duration of operation (104 +/- 28 versus 140 +/- 28 minutes; p < 0.01), less blood loss (312 +/- 167 versus 788 +/- 365 mL; p < 0.01), shorter ventilatory support (7.7 +/- 4.1 versus 12.9 +/- 3.4 hours; p < 0.01), and a shorter postoperative hospital stay (4.4 +/- 1.7 versus 7.7 +/- 2.6 days; p < 0.01) than the patients who underwent the conventional procedure.
                These data suggest that patients who undergo minimally invasive coronary artery bypass grafting have a significant reduction in the systemic inflammatory response, postoperative morbidity, and hospital stay compared with patients who undergo conventional coronary artery bypass grafting with cardiopulmonary bypass. Preoperative renal insufficiency is a predictor of acute renal failure in patients undergoing coronary artery revascularization with cardiopulmonary bypass. Off-pump coronary artery bypass grafting has been shown to be less deleterious than on-pump bypass in patients with normal renal function, but the effect of this technique in patients with non-dialysis dependent renal insufficiency in a randomized study is unknown.
                From August 2004 through October 2005, 116 consecutive patients with preoperative non-dialysis-dependent renal insufficiency (glomerular filtration rate measured using the Modification of Diet in Renal Disease equation [MDRD GFR] < or = 60 mL x min(-1) x 1.73 m(-2)) undergoing primary coronary artery bypass grafting were randomized to on-pump (n = 60) and off-pump (n = 56) groups. MDRD GFR and serum creatinine levels were measured preoperatively and postoperatively at days 1 and 5. The changes in renal function and clinical outcomes were compared between the two groups.
                Preoperative characteristics were comparable between the two groups. The repeated-measures analysis of variance was performed on the data that showed worsening of renal function in the on-pump group compared with the off-pump group (serum creatinine, P < .000; glomerular filtration rate, P < .000). Further analysis of subgroups of patients with diabetes alone, hypertension alone, and combined hypertension and diabetes also showed significant deterioration renal function in the on-pump group compared with the off-pump group. In covariate analysis, diabetes has emerged as a significant covariate by serum creatinine criteria while compromised left ventricular function has emerged as a significant covariate by glomerular filtration rate criteria. These analyses showed that the use of cardiopulmonary bypass is significantly associated with adverse renal outcome (P < .000). Three patents required hemodialysis in the on-pump group and none in the off-pump group. The mean number of grafts per patient was 3.85 +/- 0.86 and 3.11 +/- 0.89 in the on-pump and off-pump groups, respectively (P < .001), but the indices of completeness of revascularization, 1.00 +/- 0.08 for off-pump coronary bypass and 1.01 +/- 0.08 for on-pump coronary bypass, were similar (P = .60).
                This study suggests that on-pump as compared with off-pump coronary artery bypass grafting is more deleterious to renal function in diabetic patients with non-dialysis dependent renal insufficiency. MDRD GFR is a more sensitive investigation than serum creatinine levels to assess renal insufficiency in patients undergoing coronary bypass. We investigated the efficacy of coronary surgery with or without cardiopulmonary bypass in protecting the function of the small intestine, liver, and pancreas.
                Patients were randomized to off-pump coronary artery bypass grafting (OPCAB) or coronary artery bypass grafting with cardiopulmonary bypass (CABG-CPB). Small intestine function was assessed by differential four sugars (O = methyl-D-glucose, D-xylose, L-rhamnose, and lactulose) permeability and absorption tests. Liver function was assessed by monoethylglycinexylidide/lidocaine ratios and by serial measurements of transaminases (aspartate transaminase and alanine-amino transferase), bilirubin, and alkaline phosphatase. Pancreatic function was assessed by serial measurements of insulin/glucagon ratio, amylase, and glucose. Forty patients were recruited (20 per group).
                Permeability and absorption were more impaired in the OPCAB group immediately after surgery, but returned to baseline levels in both groups by postoperative day 5 (interaction of surgery type and time; p = 0.05 and p = 0.02, respectively). Monoethylglycinexylidide/lidocaine ratios were not different in the two groups. Aspartate transaminase and alanine-amino transferase levels were higher in the CABG-CPB group for the first postoperative day, but levels converged by day 3 (interaction of surgery type and time; p < 0.0001 and p = 0.04, respectively). The bilirubin level for the OPCAB group overshot the CABG-CPB group at 36 hours before returning to a similar level 60 hours postoperatively. Amylase levels were higher in the CABG-CPB group than in the OPCAB group (1.17 times; p = 0.03); other markers of pancreatic function showed no differences between the groups.
                Early small intestine function is worse with OPCAB; all functions recover to similar levels in both groups by day 5. Conversely, pancreatic function is worse with the CABG-CPB group than with the OPCAB group. Hepatic metabolic function does not differ by type of surgery to the end of the operation. Postoperative hepatocellular injury was worse with the CABG-CPB group. Coronary artery bypass graft surgery with cardiopulmonary bypass is a safe, routine procedure. Nevertheless, significant morbidity remains, mostly because of the body's response to the nonphysiological nature of cardiopulmonary bypass. Few data are available on the effects of off-pump coronary artery bypass graft surgery (OPCAB) on cardiac events and long-term clinical outcomes.
                In a single-center randomized trial, 308 patients undergoing coronary artery bypass graft surgery were randomly assigned: 155 to OPCAB and 153 to on-pump CAB (ONCAB). Primary composite end points were death, myocardial infarction, further revascularization (surgery or angioplasty), or stroke. After 5-year follow-up, the primary composite end point was not different between groups (hazard ratio 0.71, 95% CI 0.41 to 1.22; P=0.21). A statistical difference was found between OPCAB and ONCAB groups in the duration of surgery (240±65 versus 300±87.5 minutes; P<0.001), in the length of ICU stay (19.5±17.8 versus 43±17.0 hours; P<0.001), time to extubation (4.6±6.8 versus 9.3±5.7 hours; P<0.001), hospital stay (6±2 versus 9±2 days; P<0.001), higher incidence of atrial fibrillation (35 versus 4% of patients; P<0.001), and blood requirements (31 versus 61% of patients; P<0.001), respectively. The number of grafts per patient was higher in the ONCAB than the OPCAB group (2.97 versus 2.49 grafts/patient; P<0.001).
                No difference was found between groups in the primary composite end point at 5-years follow-up. Although OPCAB surgery was related to a lower number of grafts and higher episodes of atrial fibrillation, it had no significant implications related to long-term outcomes. Clinical Trial Registration-URL: http://www.controlled-trials.com. Unique identifier: ISRCTN66068876. Previous trials of off-pump coronary artery bypass (OPCAB) have enrolled selected patients and have not rigorously evaluated long-term graft patency. A preliminary report showed OPCAB achieved improved inhospital outcomes, similar completeness of revascularization, and shorter lengths of stay compared with conventional coronary artery bypass grafting (CABG).
                To assess graft patency, clinical and quality-of-life outcomes, and cost among patients while in the hospital and at 1-year follow-up.
                Randomized controlled trial of patients unselected for coronary anatomy, ventricular function, or comorbidities between March 10, 2000, and August 20, 2001, at a US academic center. A total of 200 patients were enrolled; 3 patients were withdrawn after randomization for mitral valve repair or replacement. Follow-up was complete for 197 patients at 30 days; 185 at 1 year.
                One surgical session consisting of elective OPCAB or CABG with cardiopulmonary bypass. The surgeon had extensive experience performing off-pump surgery; patients were subsequently managed by blinded protocols.
                Coronary angiography documented graft patency prior to hospital discharge and at 1 year; health-related quality of life; and cost of the index and subsequent hospitalization(s).
                Graft patency was similar for OPCAB and conventional CABG with cardiopulmonary bypass at 30 days (absolute difference, 1.3%; 95% confidence interval [CI], -0.66% to 3.31%; P =.19) and at 1 year (absolute difference, -2.2%; 95% CI, -6.1% to 1.7%; P =.27). Rates of death, stroke, myocardial infarction, angina, and reintervention were similar at 30 days and 1 year. There were no significant differences in health-related quality of life. Mean total hospitalization cost per patient at hospital discharge was 2272 dollars (95% CI, 755 dollars-3732 dollars) less for OPCAB (P =.002) and 1955 dollars (95% CI, -766 dollars to 4727 dollars) less at 1 year (P =.08).
                In this randomized single-surgeon trial among unselected patients with angiographic follow-up, OPCAB achieved similar graft patency in the hospital and at 1 year. Cardiac outcomes and health-related quality of life at 30 days and 1 year were similar and patients incurred a lower cost. OPCAB may provide complete revascularization that is durable and cost-effective. Cardiopulmonary bypass seems to be a major cause for both intraoperative microemboli and cerebral hypoperfusion. This study investigates high intensive transient signals (HITS) in transcranial Doppler ultrasound (TCD) and serum levels of the neurobiochemical marker protein S-100 in patients who underwent coronary artery bypass operation without cardiopulmonary bypass (off-pump CABG) in comparison with the conventional procedure using cardiopulmonary bypass (CPB). The results are related to the neuropsychologic outcome in both surgical groups.
                Forty patients were randomized in 2 groups (20 conventional and 20 off-pump CABG). Neurocognitive status was assessed preoperatively and postoperatively. Venous serum levels of S-100 protein were measured before and after coronary operation, HITS were measured in the middle cerebral artery during the operation.
                The median value of HITS was 394.5 (0 to 2217) in the conventional versus 11 (0 to 50) in the off-pump group, p less than 0.0001. Postoperative S-100 serum levels were: 3.76 (0.13 to 11.2) microg/L (conventional) versus 0.13 (0.04 to 1.01) microg/L (off-pump), p less than 0.0001. Postoperative cognitive testing showed significantly different results with a postoperative impairment of 90% of the patients in the conventional group versus no impairment in the off-pump group.
                Cognitive impairment seems to be strongly associated to CPB and the occurrence of micro-emboli. The off-pump technique appears to be promising in order to eliminate the source of these neuropyschologic impairments following CABG operation. Off-pump coronary bypass surgery has become a widely used technique during recent years. However, limited data are available with regard to 1-year patency of bypass grafts implanted on the beating heart in unselected consecutive bypass surgery candidates. The aim of this study was to compare 1-year angiographic patency of bypass grafts done on the beating heart (off pump) with those done classically (on pump).
                The PRAGUE-4 trial randomized 400 consecutive nonselected cardiac surgery candidates into group A (on pump; n=192) and group B (off pump; n=208). One-year follow-up coronary angiography was done in 255 patients. The arterial graft patency after 1 year was 91% in both groups. Saphenous graft patency was 59% (on pump) versus 49% (off pump; P=NS). Saphenous graft patency per patient was lower in the off-pump group: 0.7 patent anastomosis per patient versus 1.1 patent anastomosis in the on-pump group (P<0.01). There were 46% on-pump patients with all grafts patent versus 52% off-pump patients (P=NS). Grafts anastomosed distally to collateralized chronic total occlusions of native coronary arteries remained patent in 100% on the left anterior descending artery compared with 23% on other arteries (P<0.0001).
                The patency of arterial coronary bypass grafts done on the beating heart is excellent and equal to grafts done on pump. The off-pump procedure in the unselected patient population results in fewer patent saphenous grafts per patient. Cardiopulmonary bypass has been implicated in causing poor pulmonary gas exchange postoperatively in patients undergoing coronary artery bypass grafting procedures. This randomized prospective study was conducted to determine whether patients undergoing coronary artery bypass grafting operations using cardiac stabilization and thereby avoiding cardiopulmonary bypass will have improved pulmonary function postoperatively.
                Fifty-eight patients were randomized to one of two groups: coronary artery bypass grafting operation with stabilization or coronary artery bypass grafting operation with cardiopulmonary bypass. Preoperative and postoperative pulmonary gas exchange measurements were performed on intubated patients, including the arterial partial pressure of oxygen on 100% inspired oxygen, the alveolar-arterial oxygen gradient, and pulmonary shunt. Static and dynamic lung compliance measurements were performed postoperatively. Hemodynamic variables (including creatine kinase-MB and troponin levels), intubation time, postoperative bleeding, and blood transfusions were compared.
                Both study groups had a large decrease in arterial partial pressure of oxygen on 100% inspired oxygen (p < 0.0001) and a significant postoperative increase in the alveolar-arterial oxygen gradient (p < 0.0001). There was no statistical difference in the postoperative gas exchange between the two groups; however, the postoperative pulmonary shunt was significantly better in the stabilization group (24% versus 31%, p = 0.03). The patients were extubated in the intensive care unit earlier in the stabilization group (8.2 hours versus 9.2 hours, not significant). The mean static and dynamic lung compliance postoperatively was lower in the stabilization group, although not statistically significant (p = 0.06).
                Coronary artery bypass grafting operation using cardiac stabilization technique is safe and avoids the risk of cardiopulmonary bypass. The pulmonary gas exchange postoperatively is comparable to standard cardiopulmonary bypass procedures, but a reduced postoperative pulmonary shunt was seen in the stabilization group. There is increased interest in coronary artery bypass grafting (CABG) without cardiopulmonary bypass (CPB), although the preservation of the myocardium under such circumstances has not been properly investigated. The aim of this randomized study was to compare the changes in myocardial metabolism during CABG with and without CPB.
                Myocardial energy metabolism and tissue injury during CABG was monitored in a series of 22 patients (11 with and 11 without CPB).
                The maximum myocardial lactate production was significantly higher (p = 0.02) in the group operated with CPB (0.56 mmol/L) than without it (0.17 mmol/L). A similar phenomenon was seen in the transcardiac pH differences (0.085 and 0.034 with and without CPB, p = 0.007). The postoperative peak values of creatine kinase-MB mass (15.1 vs 6.3 microg/L) and troponin I (13.8 vs 5.2 microg/L) were significantly higher (p < 0.001 and p = 0.008) with than without CPB.
                CABG on a beating heart is associated with better myocardial energy preservation and less myocardial damage compared with conventional CABG with CPB and intermittent antegrade mild hypothermic blood cardioplegia. It has been previously shown that a persistent (up to 1 month) prothrombotic status occurs after coronary bypass surgery performed both on pump and off pump. To assess the pathways involved in the occurrence of postoperative prothrombotic state, in this study we evaluated plasma, monocyte-bound, and platelet-bound tissue factor expression, as well as platelet and soluble P-selectin expression, up to 1 month after off-pump and on-pump coronary artery bypass grafting.
                Thirty patient candidates for coronary surgery were randomized to undergo off-pump coronary artery bypass grafting (n = 15) or on-pump coronary artery bypass grafting (n = 15). Blood samples were collected before the intervention, after protamine administration, and 4, 8, and 30 days after surgical intervention.
                Plasma tissue factor levels were significantly higher than baseline both in the on-pump coronary artery bypass grafting group (from protamine administration up to 4 postoperative days) and in the off-pump coronary artery bypass grafting group (at 4 postoperative days), with no differences between groups. Basal and lipopolysaccharide-stimulated monocyte tissue factor expression, as well as basal and adenosine diphosphate-stimulated platelet tissue factor expression, did not show significant variations over time and were similar in the on-pump and off-pump coronary artery bypass grafting groups throughout the course of the study. Platelet expression of P-selectin, both basal and after adenosine diphosphate stimulation, did not significantly change over time and was not different in the on-pump and off-pump coronary artery bypass grafting groups. Soluble P-selectin levels in plasma were significantly higher in patients receiving on-pump coronary artery bypass grafting only at the time point after protamine administration, whereas this variable behaved similarly in the on-pump and off-pump coronary artery bypass grafting groups for the whole postoperative period.
                The postoperative tissue factor and P-selectin expression did not differ between the on-pump and off-pump coronary artery bypass grafting groups. The distinct increase of plasma tissue factor occurring after both surgical procedures might represent a mechanism that might explain, in part, the early postoperative prothrombotic state occurring after on-pump and off-pump coronary artery bypass grafting. The aim of this study was to monitor and compare the changes in metabolism and blood flow in the skeletal muscles during cardiac operations performed with cardiopulmonary bypass (CPB) and operations without CPB (off-pump) by means of interstitial microdialysis (Figure 1). Surgical revascularization, coronary artery bypass grafting (CABG), was performed in 40 patients randomized to two groups. Twenty patients (On-Pump Group) were operated on using CPB, 20 patients (Off-Pump Group) were operated on without CPB. Interstitial microdialysis was performed by 2 probes of a CMA 60 (CMA Microdialysis AB, Solna, Sweden) inserted into the patient's deltoid muscle. Microdialysis measurements were performed at 30-minute intervals. Glucose, lactate, pyruvate and glycerol as markers of basic metabolism and tissue perfusion were measured in samples from the first probe, using a CMA 600 Analyzer (CMA Microdialysis AB). Blood flow through the interstitium was monitored by means of dynamic microdialysis of ethanol as a flow-marker in the dialysates taken from the second probe (ethanol dilution technique). Results in both the groups were statistically processed and compared. Both the groups were similar in respect of preoperative characteristics. Dynamic changes of interstitial concentrations of the measured analytes were found in both the patient groups (on-pump vs. off-pump) during the operation. There was no significant difference in dialysate concentrations of glucose and lactate between the groups. Significant differences were detected in pyruvate and glycerol interstitial concentrations, lactate/pyruvate ratio and lactate/glucose ratio between the on-pump vs. off-pump patients. In the Off-Pump Group, pyruvate concentrations were higher and the values of concentrations of glycerol lower. The lactate/pyruvate ratio and the lactate/glucose ratio, indicating the aerobic and anaerobic tissue metabolism status, were lower in the Off-Pump Group. There was no significant difference in dialysate concentrations of ethanol as a flow-marker during the surgery in either of the groups. There was no statistically significant difference between the groups (On-Pump Group vs. Off-Pump Group) comparing the postoperative clinical outcome (ICU stay, ventilation duration, length of hospital stay). The dynamic changes in the interstitial concentrations of the glucose, glycerol, pyruvate and lactate were found in both the groups of patients (On-Pump Group and Off-Pump Group), but there was no difference in local blood flow when the ethanol dilution technique was used. These results showed significantly higher aerobic metabolic activity of the peripheral tissue of patients in the Off-Pump Group vs. the On-Pump Group during the course of cardiac revascularization surgery. Results suggest that extracorporeal circulation, cardiopulmonary bypass, compromises peripheral tissue (skeletal muscles) energy metabolism. These changes have no impact on the postoperative clinical outcome; no significant difference between the groups was found. To compare the safety and efficacy of coronary artery bypass grafting without using extracorporeal circulation with standard cardiopulmonary bypass technique, based on certain early postoperative criteria, we designed a fully randomized and prospective study on two similar groups of 25 patients (off-pump and on-pump groups). The groups were compared for hemodynamic data (cardiac index, systemic vascular resistance, left- and right-ventricular stroke-work indices, inotropic and mechanical support needs) and enzyme levels (CK-MB and SGOT), as well as mortality, perioperative infarction rate, homologous transfusion requirements, and the symptomatology in the first follow-ups. There was no mortality or perioperative myocardial infarction in either group. Inotropic (25% vs. 4%) and mechanical (4% vs. 0) support requirements and homologous blood consumption (percentages of patients that needed no transfusion: 20% vs. 72%) were greater in the on-pump group. Results were otherwise similar. It is concluded that, in technically suitable cases, off-pump coronary artery bypass surgery is as safe and efficient as the standard on-pump technique and can be used in particular when cannulation, hypothermia, or cardiopulmonary bypass must be avoided. With these properties, this technique could take an important place in the cardiac surgeon's armamentarium. After more than a decade of experience with off-pump coronary bypass surgery, still no consensus exists concerning its benefit on clinical outcome compared to the on-pump technique. In this 12-month follow-up, we compare off-pump and on-pump surgery on the appearance of graft patency, myocardial function, and clinical outcome.
                One hundred twenty patients were randomized to off-pump or on-pump coronary surgery. Angiography was performed intraoperatively, at 3 and 12 months. Global myocardial function was estimated by magnetic resonance imaging (MRI) preoperatively and 12 months postoperatively, as well as functional class and stress testing.
                After 12 months internal mammary artery patency was 94% in the off-pump group and 96% in the on-pump group. Vein graft patency was 80% and 87%, respectively. No statistically significant difference between the two groups existed. There were no differences in exercise capacity improvement and attenuation of symptoms between the groups.
                At 12-months follow-up, off-pump coronary bypass surgery provided the same angiographic graft patency as the on-pump technique. Improvement in functional class and exercise capacity was the same in both groups. Coronary-artery bypass grafting (CABG) has traditionally been performed with the use of cardiopulmonary bypass (on-pump CABG). CABG without cardiopulmonary bypass (off-pump CABG) might reduce the number of complications related to the heart-lung machine.
                We randomly assigned 2203 patients scheduled for urgent or elective CABG to either on-pump or off-pump procedures. The primary short-term end point was a composite of death or complications (reoperation, new mechanical support, cardiac arrest, coma, stroke, or renal failure) before discharge or within 30 days after surgery. The primary long-term end point was a composite of death from any cause, a repeat revascularization procedure, or a nonfatal myocardial infarction within 1 year after surgery. Secondary end points included the completeness of revascularization, graft patency at 1 year, neuropsychological outcomes, and the use of major resources.
                There was no significant difference between off-pump and on-pump CABG in the rate of the 30-day composite outcome (7.0% and 5.6%, respectively; P=0.19). The rate of the 1-year composite outcome was higher for off-pump than for on-pump CABG (9.9% vs. 7.4%, P=0.04). The proportion of patients with fewer grafts completed than originally planned was higher with off-pump CABG than with on-pump CABG (17.8% vs. 11.1%, P<0.001). Follow-up angiograms in 1371 patients who underwent 4093 grafts revealed that the overall rate of graft patency was lower in the off-pump group than in the on-pump group (82.6% vs. 87.8%, P<0.01). There were no treatment-based differences in neuropsychological outcomes or short-term use of major resources.
                At 1 year of follow-up, patients in the off-pump group had worse composite outcomes and poorer graft patency than did patients in the on-pump group. No significant differences between the techniques were found in neuropsychological outcomes or use of major resources. (ClinicalTrials.gov number, NCT00032630.).
                Copyright 2009 Massachusetts Medical Society. We sought to compare the effects on ophthalmic function of coronary artery bypass grafting (CABG) with cardiopulmonary bypass (CPB) and off-pump (OPCAB) grafting and to investigate whether retinal microvascular damage is associated with markers of cerebral injury.
                Retinal microvascular damage was assessed by fluorescein angiography and color fundus photography. Ophthalmic function was tested by the logarithm of the minimum angle of resolution visual acuity (VA), and cerebral injury, by transcranial Doppler ultrasound-detected emboli and S100 protein values. Twenty patients were randomized. Fluorescein angiography and postoperative VA could not be obtained for 1 CABG-CPB patient. Retinal microvascular damage was detected in 5 of 9 CABG-CPB but in none of 10 OPCAB patients (risk difference, 55%; 95% confidence interval [CI], 23% to 88%; P=0.01). Color fundus photography detected microvascular damage in 1 CABG-CPB patient but in no OPCAB patients; this lesion was associated with a field defect, which remained after 3 months of follow-up. There was no difference in postoperative VA. Doppler high-intensity transient signals (HITS) were 20.3 times more frequent in the CABG-CPB than in the OPCAB group (95% CI, 9.1 to 45; P<0.0001). Protein S100 levels were higher in the CABG-CPB than in the OPCAB group 1 hour after surgery (P<0.001). HITS were 14.7 times more frequent (95% CI, 3.5 to 62; P=0.001) and S100 level 2.1 times higher (95% CI, 1.3 to 3.5; P=0.005) when retinal microvascular damage was present.
                The relative frequency of retinal microvascular damage between groups shows the extent to which the risk of cerebral injury is reduced with OPCAB. Imaging of part of the cerebral circulation provides evidence to validate markers of cerebral injury. This study sought to assess inflammation activation in the follow-up (up to one month) of coronary bypass surgery performed both on- (CABG) and off-pump (OPCAB).
                Thirty patients, candidates for coronary surgery, were randomized to undergo CABG (n = 16) or OPCAB (n = 14). Blood samples were collected before the intervention, after protamine administration, and 4, 8, and 30 days after surgery.
                Plasma tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) levels significantly increased with respect to baseline from protamine administration up to eight postoperative days, whereas high-sensitivity C-reactive protein (hs-CRP) and fibrinogen increased after surgery up to eight postoperative days in both groups. On the other hand, neutrophil elastase levels were higher than baseline from protamine administration up to four postoperative days in CABG, and at the time point eight days after surgery in OPCAB. The only significant differences between CABG and OPCAB in inflammatory markers occurred intraoperatively, after protamine administration, when TNF-alpha and elastase levels were higher in CABG, whereas no differences were detected between CABG and OPCAB at any postoperative time point. Postoperative increases in fibrinogen and hs-CRP were positively correlated with increases in IL-6, but not with postoperative changes in TNF-alpha both in CABG and OPCAB.
                After coronary bypass surgery, there is a protracted postoperative activation of inflammation persisting several days after surgery; this postoperative activation is not affected by the surgical strategy (on-pump or off-pump). Neurologic and clinical morbidity after coronary artery bypass grafting (CABG) can be significant. By avoiding cardiopulmonary bypass, off-pump CABG (OPCAB) may reduce morbidity.
                Sixty patients (30 CABG and 30 OPCAB) were prospectively randomized. Neurocognitive testing was performed before the operation and 2 weeks and 1 year after the operation. Neurologic testing to detect stroke and (99m)Tc-HMPAO whole-brain single photon emission computed tomography scanning to assess cerebral perfusion were performed before the operation and 3 days afterward. Bilateral middle cerebral artery transcranial Doppler scanning was performed intraoperatively to detect cerebral microemboli. All examiners were blinded to treatment group. Clinical morbidity and costs were compared.
                Coronary artery bypass grafting was associated with more cerebral microemboli (575 +/- 278.5 CABG versus 16.0 +/- 19.5 OPCAB (median +/- semiinterquartile range) and significantly reduced cerebral perfusion after the operation to the bilateral occipital, cerebellar, precunei, thalami, and left temporal lobes (p < or = 0.01). Cerebral perfusion with OPCAB was unchanged. Compared with base line, OPCAB patients performed better on the Rey Auditory Verbal Learning Test (total and recognition scores) at both 2 weeks and at 1 year (p < or = 0.05), whereas CABG performance was statistically unchanged for all cognitive measures. Patients who underwent CABG had more chest tube drainage (1389 +/- 1256 mL CABG versus 789 +/- 586 mL OPCAB, p = 0.02) and required more blood (3.9 +/- 5.8 U CABG versus 1.2 +/- 2.2 U OPCAB, p = 0.02), fresh frozen plasma (3.0 +/- 6.0 U CABG versus 0.5 +/- 2.2 U OPCAB, p = 0.03), and hours of postoperative use of dopamine (16.3 +/- 21.2 hours CABG versus 7.3 +/- 9.7 hours OPCAB, p = 0.04). These differences culminated in higher costs for CABG ($23,053 +/- $5,320 CABG versus $17,780 +/- $4,390 OPCAB, p < 0.0001). One stroke occurred with CABG, compared with none with OPCAB (p = NS). One OPCAB patient died because of a pulmonary embolus (p = NS).
                Compared with CABG, OPCAB may reduce neurologic and clinical morbidity as well as cost. Cardiopulmonary bypass (CPB) has been reported to increase oxygen metabolism and to influence the relation between oxygen consumption (VO(2)) and delivery (DO(2)) in the early hours after cardiac surgery. To investigate the role of CPB, we studied oxygen metabolism in coronary artery bypass procedures performed on-pump (CABG) and off-pump (OPCAB).
                Twenty-five patients were randomized to undergo CABG (n = 14) or OPCAB (n = 11). All patients received the same anesthetic management. Oxygen metabolism variables were assessed before induction of anesthesia and up to 18-hours after surgery.
                At baseline, before induction of anesthesia, there were no differences between CABG and OPCAB in oxygen consumption (VO(2)), delivery (DO(2)), or extraction (ExO(2)). After surgery VO(2) and ExO(2) increased in both groups, while DO(2) decreased. No significant differences between CABG and OPCAB were detected in postoperative VO(2), DO(2), and ExO(2) levels. The relation between VO(2) and DO(2) was very similar in CABG and OPCAB patients throughout the study, and no significant differences were detected in slopes and intercepts of the regression lines between CABG and OPCAB at all time points. There was, however, a significant effect of time on the relation between VO(2) and DO(2): this relation was stronger in the postoperative period, and the slope of this relation increased over time as well.
                A hypermetabolic state and progressive and significant increases in the strength of the relationship between VO(2) and DO(2) and in the slope of this relationship occur after both CABG and OPCAB. Cardiopulmonary bypass is not responsible for these changes in oxygen metabolism. In this study, we test the hypothesis that off-pump coronary bypass surgery might result in less lymphocyte activation than on-pump coronary surgery. We also study the behavior of lymphocyte activation markers during and after surgery.
                Coronary artery bypass surgery is known to be associated with changes of inflammatory mediators, immune function, and early phase lymphocyte activation, which could cause postoperative lymphopenia and lymphocyte unresponsiveness.
                We studied lymphocyte activation response in 28 patients randomized to off-pump (n = 13) or on-pump (n = 15) coronary artery bypass surgery. Expression of CD25, CD26, CD69, and DR on T (CD3+) and B (CD19+) lymphocytes on peripheral blood was assessed through flow cytometry.
                The response of T lymphocytes and their activation markers, as well as B lymphocytes and their activation markers, was similar after on- and off-pump surgery. Overall, T lymphocytes decreased to the lowest level 9 h after surgery and tended to increase later. For B lymphocytes, there was early reduction with increase on the 1st postoperative day. There was early activation of CD69+ and late activation of CD25+ on T lymphocytes. For B lymphocytes, there was early activation of CD69+ and late activation of DR+.
                (1) Compared to on-pump cardiopulmonary bypass, off-pump surgery does not reduce lymphocyte activation. (2) Coronary bypass surgery causes the early activation of lymphocytes, as evidenced by the increased expression of lymphocyte activation markers. Gastrointestinal complications after cardiac surgery remain a significant problem despite improvements in pre-operative, operative and post-operative care. The pathophysiology is uncertain, and their prevention remains suboptimal. This prospective, randomised study was designed to define the role of cardiopulmonary bypass (CPB) and cardioplegic arrest in the pathogenesis of gastrointestinal complications following coronary artery surgery.
                Three hundred patients were prospectively randomised to (1) on-pump conventional coronary artery surgery [150 patients, 114 men, mean age 64 (45-75 years)] with mild hypothermic (32c) CPB and cardioplegic arrest of the heart or (2) off-pump surgery [150 patients, 113 men, mean age 64 (38-66) years] on the beating heart. The association of perioperative factors with gastrointestinal complications was investigated by univariate analysis. Significant variables were then included into a stepwise logistic regression model to ascertain their independent influence on the occurrence of gastrointestinal complications. There were no significant baseline differences between the groups. Eleven patients in the on-pump group and one patient in the off-pump group had post-operative gastrointestinal complications. Univariate analysis showed that CPB inclusive of cardioplegic arrest, left ventricular ejection fraction <50%, emergency surgery, prolonged aortic cross clamp and CPB time, post-operative low cardiac output syndrome, post-operative inotropic requirement, new onset atrial fibrillation (AF), excessive post-operative blood loss and redo thoracotomy <24 hours were predictors of gastrointestinal complications after coronary artery surgery (all p<0.05). However, stepwise multivariate regression analysis identified CPB inclusive of cardioplegic arrest as the only predictor of post-operative gastrointestinal complications (OR7.4; CI 3.4-17.9).
                Cardiopulmonary bypass, inclusive of cardioplegic arrest, is the main independent predictor of post-operative gastrointestinal complications in patients undergoing coronary revascularisation. Off-pump CABG is potentially associated with reduced intraoperative blood loss and homologous blood transfusion in comparison to on-pump CABG. In this randomised controlled study we investigated the effects of autologous cell saver blood transfusion on blood loss and homologous blood transfusion requirements in patients undergoing CABG on- versus off-CPB.
                Eighty patients were randomised into one of four groups: (A) on-CPB with cell saver blood transfusion (CSBT), (B) on-CPB without CSBT, (C) off-pump with CSBT and (D) off-pump without CSBT. Volume of intraoperative autologous blood transfusion, postoperative mediastinal blood loss and homologous blood transfusion requirements were measured. Homologous blood was transfused when haemoglobin concentration fell below 8 g/dl postoperatively. Pre- and postoperatively prothrombin time and partial thromboplastin time were measured.
                Preoperative patient characteristics were well matched among the four groups. The amount of salvaged mediastinal blood available for autologous transfusion was significantly higher in the on-pump group (A) compared to the off-CPB group (C) (433+/-155 ml vs 271+/-144 ml, P=0.001). Volume of homologous blood transfusion was significantly higher in group B vs groups A, C and D (595+/-438 ml vs 179+/-214, 141+/-183 and 230+/-240 ml, respectively, P<0.005). The cell saver groups (A and C) received significantly less homologous blood than the groups without cell saver (160+/-197 ml vs 413+/-394 ml, respectively, P<0.005). Patients undergoing off-CPB surgery received significantly less homologous blood than those undergoing on-CPB CABG irrespective of cell saver blood transfusion (184+/-214 ml vs 382+/-397 ml, P<0.05). Postoperative blood loss was similar in the four groups (842+/-276, 1023+/-291, 869+/-286 and 903+/-315 ml in groups A to D, respectively, P>0.05). Clotting test results revealed no significant difference between the groups. There was no significant difference in postoperative morbidity between groups.
                Off-pump CABG is associated with significant reduction in intraoperative mediastinal blood loss and homologous transfusion requirements. Autologous transfusion of salvaged washed mediastinal blood reduced homologous transfusion significantly in the on-CPB group. Cell saver caused no significant adverse impact on coagulation parameters in on- or off-CPB CABG. Postoperative morbidity and blood loss were not affected by the use of CPB or autologous blood transfusion. We recommend the use of autologous blood transfusion in both on- and off-pump CABG surgery. We hypothesized that off-pump coronary artery bypass grafting has less impact on the hemostatic systems than on-pump surgery.
                Thirty-one patients were randomized to on-pump or off-pump coronary artery bypass grafting. Factors of hemostasis as well as markers of endothelial activation were measured up to 24 hours after the operation: Fibrin D dimer, prothrombin fragment 1+2, alpha2-macroglobulin, protein C1 esterase inhibitor, fibronectin, and von Willebrand factor. Overall hemostasis potential, overall coagulation potential, and overall fibrinolysis potential were determined with a previously developed assay. We also measured platelet count before and after surgery.
                Fibrin D dimer and prothrombin fragment 1+2 concentrations were lower during surgery in the off-pump group (p < 0.001). Four hours after admission to the intensive care unit, these differences were eliminated. alpha2-macroglobulin, protein C1 esterase inhibitor, fibronectin, and von Willebrand factor concentrations did not differ between groups (p = 0.59, p = 0.28, p = 0.22, and p = 0.69). Protein C1 esterase inhibitor and von Willebrand factor concentrations increased over time (p < 0.001) in both groups. Overall hemostasis potential and overall coagulation potential increased over time (p < 0.001), while overall fibrinolysis potential decreased (p < 0.001) with no difference between groups (p = 0.69, p = 0.91). Platelet count decreased on the first postoperative day (p < 0.001), but increased from the first to the third postoperative day (p = 0.004) in both groups without any inter group difference (p = 0.82).
                There was a tendency toward less activation of coagulation and fibrinolysis in low-risk patients during elective off-pump coronary artery bypass surgery when compared with on-pump surgery. Conventional coronary artery bypass graft surgery with use of cardiopulmonary bypass (on-pump CABG) is associated with excellent long-term cardiac outcomes but also with a high incidence of cognitive decline. The effect of avoiding cardiopulmonary bypass (off-pump CABG) on long-term cognitive and cardiac outcomes is unknown.
                To compare the effect of off-pump CABG and on-pump CABG surgery on long-term cognitive and cardiac outcomes.
                The Octopus Study, a multicenter randomized controlled trial conducted in the Netherlands, which enrolled 281 low-risk CABG patients between 1998 and 2000. Five years after their surgery, surviving patients were invited for a follow-up assessment.
                Patients were randomly assigned to receive either off-pump (n = 142) or on-pump (n = 139) CABG surgery.
                The primary measure was cognitive status 5 years after surgery, which was determined by a psychologist blinded to treatment allocation who administered 10 standardized validated neuropsychological tests. Secondary measures were occurrence of cardiovascular events (all-cause mortality, stroke, myocardial infarction, and coronary reintervention), anginal status, and quality of life.
                After 5 years, 130 patients were alive in each group. Cognitive outcomes could be determined in 123 and 117 patients in the off-pump and on-pump groups, respectively. When using a standard definition of cognitive decline (20% decline in performance in 20% of the neuropsychological test variables), 62 (50.4%) of 123 in the off-pump group and 59 (50.4%) of 117 in the on-pump group had cognitive decline (absolute difference, 0%; 95% confidence interval [CI], -12.7% to 12.6%; P>.99). When a more conservative definition of cognitive decline was used, 41 (33.3%) in the off-pump group and 41 (35.0%) in the on-pump group had cognitive decline (absolute difference, -1.7%; 95% CI, -13.7% to 10.3%; P = .79). Thirty off-pump patients (21.1%) and 25 on-pump patients (18.0%) experienced a cardiovascular event (absolute difference, 3.1%; 95% CI, -6.1% to 12.4%; P = .55). No differences were observed in anginal status or quality of life.
                In low-risk patients undergoing CABG surgery, avoiding the use of cardiopulmonary bypass had no effect on 5-year cognitive or cardiac outcomes.
                isrctn.org Identifier: ISRCTN69438133.