Perioperative increase in global blood flow to explicit defined goals and outcomes after surgery: a Cochrane Systematic Review. Perioperative Morbidity in Patients Randomized to Epidural or General Anesthesia for Lower Extremity Vascular Surgery Outcomes in patients with chest pain evaluated in a chest pain unit: the chest pain evaluation in the emergency room study cohort. Effect of mivazerol on perioperative cardiac complications during non-cardiac surgery in patients with coronary heart disease: the European Mivazerol Trial (EMIT). Perioperative hyperoxia - Long-term impact on cardiovascular complications after abdominal surgery, a post hoc analysis of the PROXI trial. Dietetic guidelines: diet in secondary prevention of cardiovascular disease. Small, Oral Dose of Clonidine Reduces the Incidence of Intraoperative Myocardial Ischemia in Patients Having Vascular Surgery Cardiac Outcome after Peripheral Vascular Surgery: Comparison of General and Regional Anesthesia Outcomes in patients with myocardial infarction who are initially admitted to stepdown units: data from the Multicenter Chest Pain Study. Nitrous Oxide and Serious Morbidity and Mortality in the POISE Trial Risk of Bias in Systematic Reviews of Non-Randomized Studies of Adverse Cardiovascular Effects of Thiazolidinediones and Cyclooxygenase-2 Inhibitors: Application of a New Cochrane Risk of Bias Tool Reconciling systematic reviews of exercise-based cardiac rehabilitation and secondary prevention programmes for coronary heart disease Cardiac prognosis in noncardiac geriatric surgery. No Finding of Increased Myocardial Ischemia During or After Carotid Endarterectomy Under Anesthesia With Nitrous Oxide The effect of bisoprolol on perioperative mortality and myocardial infarction in high-risk patients undergoing vascular surgery. Dutch Echocardiographic Cardiac Risk Evaluation Applying Stress Echocardiography Study Group. Late survival after perioperative myocardial infarction complicating vascular surgery. Nitrous oxide and perioperative cardiac morbidity (ENIGMA-II) Trial: rationale and design. Smoking Status and Risk for Recurrent Coronary Events after Myocardial Infarction An evaluation of facial expression displayed by patients with chest pain. Diagnostic and prognostic utility of early measurement with high-sensitivity troponin T assay in patients presenting with chest pain Nitrous Oxide and Long-Term Morbidity and Mortality in the ENIGMA Trial Effect of intravenous streptokinase as compared with that of tissue plasminogen activator on left ventricular function after first myocardial infarction. The influence of perioperative myocardial infarction on long-term prognosis following elective vascular surgery. The defibrillator in acute myocardial infarction trial (DINAMIT): study protocol. Ruling out acute myocardial infarction. A prospective multicenter validation of a 12-hour strategy for patients at low risk. Is general anesthesia a risk for myocardium? Effect of anesthesia on myocardial function as assessed by cardiac troponin-i in two different groups (isofluran+N2O inhalation and propofol+fentanyl iv anesthesia) Neuraxial block, death and serious cardiovascular morbidity in the POISE trial. Vascular events in healthy older women receiving calcium supplementation: randomised controlled trial Prospective validation of artificial neural network trained to identify acute myocardial infarction Diagnostic and prognostic value of dipyridamole echocardiography in patients with suspected coronary artery disease. Comparison with exercise electrocardiography. Effect of glycoprotein IIb/IIIa receptor blocker abciximab on outcome in patients with acute coronary syndromes without early coronary revascularisation: the GUSTO IV-ACS randomised trial. Representation of elderly persons and women in published randomized trials of acute coronary syndromes. Perioperative red blood cell transfusion and outcome in stable patients after elective major vascular surgery. Perioperative beta blockade with propranolol: reduction in myocardial oxygen demands and incidence of atrial and ventricular arrhythmias. Low-dose and high-dose acetylsalicylic acid for patients undergoing carotid endarterectomy: a randomised controlled trial
This systematic review and meta- analysis summarizes the clinical effects of increasing perioperative blood flow using fluids with or without inotropes/vasoactive drugs to explicit defined goals in adults . We included r and omized controlled trials of adult patients ( aged 16 years or older ) undergoing surgery . We included 31 studies of 5292 participants . There was no difference in mortality at the longest follow-up : 282/2615 ( 10.8 % ) died in the control group and 238/2677 ( 8.9 % ) in the treatment group , RR of 0.89 ( 95 % CI : 0.76 - 1.05 ; P=0.18 ) . However , the results were sensitive to analytical methods and withdrawal of studies with method ological limitations . The intervention reduced the rate of three morbidities ( renal failure , respiratory failure , and wound infections ) but not the rates of arrhythmia , myocardial infa rct ion , congestive cardiac failure , venous thrombosis , and other types of infections . The number of patients with complications was also reduced by the intervention . Hospital length of stay was reduced in the treatment group by 1.16 days . There was no difference in critical care length of stay . The primary analysis of this review showed no difference between groups but this result was sensitive to the method of analysis , withdrawal of studies with method ological limitations , and was dominated by a single large study . Patients receiving this intervention stayed in hospital 1 day less with fewer complications . It is unlikely that the intervention causes harm . The balance of current evidence does not support widespread implementation of this approach to reduce mortality but does suggest that complications and duration of hospital stay are reduced Background : Perioperative morbidity may be modifiable in high risk patients by the anesthesiologist 's choice of either regional or general anesthesia . This clinical trial compared outcomes between epidural ( EA ) and general ( GA ) anesthesia/analgesia regimens In a group of patients at high risk for cardiac and other morbidity who were undergoing similarly stressful surgical procedures . Methods : One hundred patients scheduled for elective vascular reconstruction of the lower extremities were r and omized to receive either EA for surgery followed by epidural analgesia , or GA for surgery followed by intravenous patient-controlled analgesia .  Hemodynamic monitoring , blood pressure , and heart rate limits were determined prior to r and omization . Management of anesthesia in the immediate postoperative period was st and ardized . The data collected included continuous electrocardiographic monitoring from the day before surgery through the third postoperative day , serial electrocardiograms , and cardiac enzymes . Cardiac ischemia , myocardial infa rct ion , unstable angina , and cardiac death were identified by a cardiologist blinded to the type of anesthesia received . Other major morbidity was determined at the time of hospital discharge and at 1 and 6 months after surgery . Results : Eleven patients who received GA required regrafting or an embolectomy during their hospital stay , compared with two patients who received EA . This association of GA with reoperation remained significant after adjustment for baseline differences . Cardiac outcomes were similar in the two groups with respect to perioperative death ( 1 EA and 1 GA ) , death within 6 months ( 4 EA and 3 GA ) , nonfatal myocardial infa rct ion within 7 days ( 2 EA and 2 GA ) , unstable angina ( 0 EA and 2 GA ) , and myocardial ischemia following r and omization ( 17 EA and 23 GA ) . Rates of major infections in the two groups ( 1 EA and 2 GA ) , renal failure ( 3 EA and 3 GA ) , and pulmonary complications ( 3 EA and 7 GA ) also were similar . Conclusions : Carefully conducted epidural and general anesthesia appear to be associated with comparable rates of cardiac and most other morbidity in patients undergoing lower extremity vascular surgery . However , compared with general anesthesia , epidural anesthesia is associated with a lower incidence of reoperatlon for inadequate tissue perfusion and , therefore , may be advantageous for this surgical population BACKGROUND Limited data exist on the long-term outcomes of patients who undergo evaluation in a chest pain unit ( CPU ) .  METHODS Our study included patients with chest pain at intermediate risk for acute cardiovascular events enrolled in the CHEER study . The primary outcome included a composite of death , myocardial infa rct ion , acute heart failure , stroke , and out-of-hospital cardiac arrest . The secondary outcome included a composite of cardiovascular death , myocardial infa rct ion , acute heart failure , stroke , revascularization , and unstable angina . Data were obtained through a medical record review . We compared outcomes between groups r and omized to the CPU versus admission , those admitted from the CPU versus dismissed home , and those who were admitted versus dismissed home after a cardiac stress test in the emergency department . RESULTS The final analysis included 407 patients . Median surveillance length was 5.5 years . No differences in the primary outcome or secondary outcome existed between patients r and omized to the CPU versus admitted to hospital ( 21.6 % vs 20.2 % and 29.9 % vs 33.0 % , respectively , P > .05 for all comparisons ) . Patients admitted from the CPU had higher rates of the secondary outcome ( adjusted hazard ratio 2.26 ) than patients dismissed from the CPU . Patients admitted after a cardiac stress test in the CPU had higher rates of the secondary outcome ( adjusted hazard ratio 2.42 ) than patients dismissed from the CPU . CONCLUSIONS A CPU does not increase long-term adverse outcomes in patients with chest pain at intermediate risk for an acute event BACKGROUND Mivazerol is a drug with alpha2-agonist properties that reduces post-ganglionic noradrenaline availability and spinal efferent sympathetic output . METHODS A double-blind r and omized placebo-controlled trial was conducted in 61 European centers during a 2.5-yr period on 2,854 patients : 1,897 with coronary heart disease and 957 patients without overt coronary heart disease but classified as at high risk for it . The present analysis was restricted to those patients with previous known coronary heart disease of whom 48 % had vascular surgery , 32 % non-vascular thoracic or abdominal surgery , and 20 % orthopedic surgery .  Mivazerol or placebo were given intravenously from the induction of anesthesia for up to 72 h. RESULTS In the 1,897 patients with established coronary heart disease , mivazerol did not reduce the primary endpoint -- the combination of myocardial infa rct ion or death -- or all-cause deaths significantly . A preplanned subgroup analysis of 904 patients with known coronary heart disease undergoing vascular surgery showed that there were fewer primary endpoints in those receiving mivazerol ( risk ratio [ RR ] , 0.67 ; 95 % CL , 0.45 - 0.98 ; P = 0.037 ) and fewer cardiac deaths ( 6 of 454 vs. 18 of 450 : RR , 0.33 ; 95 % confidence limits , 0.13 - 0.82 ; P = 0.017 ) . The all-cause death rate was also decreased ( RR , 0.41 ; 95 % CL , 0.18 - 0.91 ; P = 0.024 ) , although there was no significant reduction in myocardial infa rct ion . CONCLUSION The alpha2-adrenergic agonist , mivazerol , did not alter the rates of myocardial infa rct ion or cardiac death in patients with known coronary heart disease undergoing noncardiac surgery . However , it may have protected patients undergoing vascular surgery from further coronary events , and a specific study of such patients is now indicated BACKGROUND Increased long-term mortality was found in patients exposed to perioperative hyperoxia in the PROXI trial , where patients undergoing laparotomy were r and omised to 80 % versus 30 % oxygen during and after surgery . This post hoc follow-up study assessed the impact of perioperative hyperoxia on long-term risk of cardiovascular events . METHODS A total of 1386 patients undergoing either elective or emergency laparotomy  were r and omised to 80 % versus 30 % oxygen during and two hours after surgery . At follow-up , the primary outcome of acute coronary syndrome was assessed . Secondary outcomes included myocardial infa rct ion , other heart disease , and acute coronary syndrome or death . Data were analysed in the Cox proportional hazards model . RESULTS The primary outcome , acute coronary syndrome , occurred in 2.5 % versus 1.3 % in the 80 % versus 30 % oxygen group ; HR 2.15 ( 95 % CI 0.96 - 4.84 ) . Patients in the 80 % oxygen group had significantly increased risk of myocardial infa rct ion ; HR 2.86 ( 95 % CI 1.10 - 7.44 ) , other heart disease ; HR 1.40 ( 95 % 1.06 - 1.83 ) , and acute coronary syndrome or death ; HR 1.22 ( 95 % CI 1.01 - 1.49 ) . CONCLUSIONS Perioperative hyperoxia may be associated with an increased long-term risk of myocardial infa rct ion and other heart disease AIM To produce dietetic guidelines summarizing the systematic review evidence on dietary advice for secondary prevention of cardiovascular disease . METHODS The Cochrane Library , MEDLINE and EMBASE were comprehensively search ed for systematic review s on aspects of diet and heart health . Review s were included if they search ed systematic ally for r and omised controlled trials relating to diet and secondary prevention of cardiovascular disease . Two members of the UK Heart Health and Thoracic Dietitians Group critically appraised each review . The quality and results of each review were discussed and summarized in a whole group meeting . The guidelines were trialled in seven dietetic departments and modified where necessary . RESULTS Providing evidence -based dietary information ( including increasing omega-3 fat plus fruit and vegetable intake ) to all people after myocardial infa rct ion will save more lives than concentrating dietary advice on those in need of weight loss or lipid lowering . The practice of prioritizing dietetic time to those with raised lipids is out of date since the advent of statin therapy . CONCLUSION There is good systematic review evidence that dietary advice to those with cardiovascular disease can reduce mortality and morbidity as well as modify risk factors .  Dietary advice that does this most effectively should be prioritized Background Most new perioperative myocardial ischemic episodes occur in the absence of hypertension or tachycardia . The ability of alpha2 ‐adrenoceptor agonists to inhibit central sympathetic outflow may benefit patients with coronary artery disease by increasing the myocardial oxygen supply‐ and ‐dem and ratio . Methods A r and omized double‐blind study design was used in 297 patients scheduled to have elective vascular surgical procedures to evaluate the effects of 2 micro gram/kg sup ‐1 oral clonidine ( n = 145 ) or placebo ( n = 152 ) on the incidence of perioperative myocardial ischemic episodes , myocardial infa rct ion , and cardiac death . Continuous real‐time S‐T segment trend analysis ( lead II and V5 ) was performed during anesthesia and surgery and correlated with arterial blood pressure and heart rate before and during ischemic events . Dose requirements for vasoactive and antiischemic drugs to control blood pressure and heart rate as well as episodes of myocardial ischemia ( i.e. , catecholamines , beta‐adrenoceptor antagonists , nitrates , and systemic vasodilators ) and fluid volume load were recorded . Results Administration of clonidine reduced the incidence of perioperative myocardial ischemic episodes from 39 % ( 59 of 152 ) to 24 % ( 35 of 145 ) ( P < 0.01 ) . Hemodynamic patterns , percentage of ischemic time , and the number of ischemic episodes per patient did not differ . Nonfatal myocardial infa rct ion developed after operation in four patients receiving placebo compared with none receiving clonidine ( day 2 to 21 ; P = 0.07 ) . The incidence of fatal cardiac events ( 1 vs. 2 ) was not different . Dose requirements for vasoactive and antiischemic drugs did not differ between the groups , but the amount of presurgical fluid volume was slightly greater in patients receiving clonidine ( 951 + /‐ 388 vs. 867 + /‐ 381 ml ; P < 0.03 ) . Conclusion A small oral dose of clonidine , given prophylactically , can reduce the incidence of perioperative myocardial ischemic episodes without affecting hemodynamic stability in patients with suspected or documented coronary artery disease Background Despite evidence that regional anesthesia may be associated with fewer perioperative complications than general anesthesia , most studies that have compared cardiac outcome after general or regional anesthesia alone have not shown major differences . This study examines the impact of anesthetic choice on cardiac outcome in patients undergoing peripheral vascular surgery who have a high likelihood of associated coronary artery disease . Methods Four hundred twenty‐three patients , between 1988 and 1991 , were r and omly assigned to receive general ( n = 138 ) , epidural ( n = 149 ) , or spinal anesthesia ( n = 136 ) for femoral to distal artery bypass surgery . All patients were monitored with radial artery and pulmonary artery catheters . Postoperatively , patients were in a monitored setting for 48–72 h and had daily electrocardiograms for 4–5 days and creatine phosphokinase/isoenzymes every 8 h x 3 , then daily for 4 days . Cardiac outcomes recorded were myocardial infa rct ion , angina , and congestive heart failure . Results Baseline clinical characteristics were not different between anesthetic groups . Overall , the patient population included 86 % who were diabetic , 69 % with hypertension , 36 % with a history of a prior myocardial infa rct ion , and 41 % with a history of smoking . Cardiovascular morbidity and overall mortality were not significantly different between groups when analyzed by either intention to treat or type of anesthesia received . In the intention to treat analysis , incidences of cardiac event or death for general , spinal , and epidural groups were 16.7 % , 21.3 % , and 15.4 % , respectively . The absolute risk difference observed between general and all regional anesthesia groups for cardiac event or death was ‐1.6 % ( 95 % confidence interval ‐9.2 % , 6.1 % ) This reflected a nonsignificant trend for lower risk of postoperative events with general anesthesia . Conclusions The choice of anesthesia , when delivered as described , does not significantly influence cardiac morbidity and overall mortality in patients undergoing peripheral vascular surgery PURPOSE To assess whether the admission of patients with chest pain to a stepdown unit would jeopardize the outcome of those patients who ultimately " ruled in " for a myocardial infa rct ion . PATIENTS AND METHODS We compared the risk of an adverse outcome in initially uncomplicated , " rule-out myocardial infa rct ion " patients who were admitted directly to a stepdown unit ( n = 58 ) or to a coronary care unit ( n = 409 ) at 6 hospitals and who then ultimately " ruled in " for a myocardial infa rct ion . RESULTS An adverse outcome ( death , serious complication , or invasive intervention ) occurred in 16 ( 28 % ) stepdown unit patients compared with 159 ( 39 % ) coronary care unit patients . Among patients eligible for initial care in either location , the risk of an adverse outcome after controlling for clinical characteristics was similar in the two groups using each of two different multivariate approaches . CONCLUSION Although our study was not of sufficient size to exclude the possibility of a small benefit from initial triage to a coronary care unit , our data suggest that ( 1 ) admission of initially uncomplicated chest pain patients with a relatively low probability of acute myocardial infa rct ion to a stepdown unit does not seriously jeopardize those who eventually " rule in " for myocardial infa rct ion ; and ( 2 ) larger observational or r and omized studies , which could reduce the residual possibility of somewhat higher risk in the stepdown unit , would be ethical to perform BACKGROUND : In this post hoc sub analysis of the Perioperative Ischemic Evaluation ( POISE ) trial , we sought to determine whether nitrous oxide was associated with the primary composite outcome of cardiovascular death , nonfatal myocardial infa rct ion ( MI ) , and nonfatal cardiac arrest within 30 days of r and omization . METHODS : The POISE trial of perioperative & bgr;-blockade was undertaken in 8351 patients .  Nitrous oxide anesthesia was defined as the coadministration of nitrous oxide in patients receiving general anesthesia  , with or without additional neuraxial blockade or peripheral nerve blockade . Logistic regression , with inverse probability weighting using estimated propensity scores , was used to determine the association of nitrous oxide with the primary outcome , MI , stroke , death , and clinical ly significant hypotension . RESULTS :  Nitrous oxide was administered to 1489 ( 29 % ) of the 5133 patients included in this analysis . Nitrous oxide had no significant effect on the risk of the primary outcome ( 112 [ 7.5 % ] vs 248 [ 6.9 % ] ; odds ratio [ OR ] , 1.08 ; 95 % confidence interval [ CI ] , 0.82–1.44 ; 99 % CI , 0.75–1.57 ; P = 0.58 ) , MI ( 89 [ 6.0 ] vs 204 [ 5.6 ] ; OR , 0.99 ; 95 % CI , 0.75–1.31 ; 99 % CI , 0.69–1.42 ; P = 0.94 ) , stroke ( 6 [ 0.4 % ] vs 28 [ 0.8 % ] ; OR , 0.85 ; 95 % CI , 0.26–2.82 ; 99 % CI , 0.17–4.11 ; P = 0.79 ) , death ( 40 [ 2.7 % ] vs 100 [ 2.8 % ] ; OR , 1.04 ; 95 % CI , 0.6–1.81 ; 99 % CI , 0.51–2.15 ; P = 0.88 ) or clinical ly significant hypotension ( 219 [ 14.7 % ] vs 544 [ 15.0 % ] ; OR , 0.92 ; 95 % CI , 0.74–1.15 ; 99 % CI , 0.70–1.23 ; P = 0.48 ) . CONCLUSIONS : In this post hoc sub analysis , nitrous oxide was not associated with an increased risk of adverse outcomes in the POISE trial patients . This analysis was limited by the observational nature of the data and the lack of information on the concentration and duration of nitrous oxide administration . Further r and omized controlled trial evidence is required Background Systematic review s of the effects of healthcare interventions frequently include non-r and omized studies . These are subject to confounding and a range of other biases that are seldom considered in detail when synthesizing and interpreting the results . Our aims were to assess the reliability and usability of a new Cochrane risk of bias ( RoB ) tool for non-r and omized studies of interventions and to determine whether restricting analysis to studies with low or moderate RoB made a material difference to the results of the review s. Methods and Findings We selected two systematic review s of population -based , controlled non-r and omized studies of the relationship between the use of thiazolidinediones ( TZDs ) and cyclooxygenase-2 ( COX-2 ) inhibitors and major cardiovascular events . Two epidemiologists applied the Cochrane RoB tool and made assessment s across the seven specified domains of bias for each of 37 component studies . Inter-rater agreement was measured using the weighted Kappa statistic . We grouped studies according to overall RoB and performed statistical pooling for ( a ) all studies and ( b ) only studies with low or moderate RoB. Kappa scores across the seven bias domains ranged from 0.50 to 1.0 . In the COX-2 inhibitor review , two studies had low overall RoB , 14 had moderate RoB , and five had serious RoB. In the TZD review , six studies had low RoB , four had moderate RoB , four had serious RoB , and two had critical RoB. The pooled odds ratios for myocardial infa rct ion , heart failure , and death for rosiglitazone versus pioglitazone remained significantly elevated when analyses were confined to studies with low or moderate RoB. However , the estimate for myocardial infa rct ion declined from 1.14 ( 95 % CI 1.07–1.24 ) to 1.06 ( 95 % CI 0.99–1.13 ) when analysis was confined to studies with low RoB. Estimates of pooled relative risks of cardiovascular events with COX-2 inhibitors compared with no nonsteroidal anti-inflammatory drug changed little when analyses were confined to studies with low or moderate RoB. The exception was a rise in the relative risk associated with ibuprofen from 1.07 ( 95 % CI 0.97–1.18 ) to 1.14 ( 95 % CI 1.03–1.26 ) . The main limitation of our study was testing the instrument on a narrow range of pharmacoepidemiological studies ; we can not assume our findings extend to a broader range of interventions and setting s. Conclusions The Cochrane RoB tool highlighted a wide range of risks of bias in studies included in two widely cited review s and had the potential to change the conclusions of the review s. Systematic review s that incorporate non-r and omized studies of medical interventions should include a detailed assessment of RoB for each included study Findings of systematic review s incorporating meta analysis are by nature hypothesis generating and should be carefully and judiciously interpreted . This need is epitomized by two of the largest review s of interventions to support risk factor reduction after a diagnosis of coronary heart disease ( Table 1 ) . These review s both included r and omized trials published in a similar timeframe ( up to 2003 or 2004 ) that compared the effects of various risk factor reduction programmes for patients with confirmed coronary heart disease to usual care . In 2004 , a Cochrane review found that supervised and unsupervised exercise-based cardiac rehabilitation provided to patients with different forms of coronary heart disease lowered all cause total mortality by 20 % and cardiac mortality by 26 % in 48 trials of 8940 patients . The review ers concluded that there was ‘ no difference in mortality effect between exercise-only cardiac rehabilitation and comprehensive cardiac rehabilitation , or by exercise dose or duration of followup ’ . Also , the exercise-based programmes did not reduce recurrent myocardial infa rct ion and the need for repeat coronary revascularization to statistically significant levels . Around the same time , a second review of 63 trials involving 21,295 patients who had undergone secondary cardiac prevention programmes found reductions of total mortality of 15 % and of acute myocardial infa rct ion of 17 % . However , in contrast to the previous review , the secondary prevention programmes significantly reduced the rate of recurrent heart attacks . Also , benefits did not differ between programmes ‘ that incorporated education and counselling about coronary risk factors with a supervised exercise programme , those that included risk factor education or counselling but no exercise component , and those that consisted of only a structured exercise programme ’ . On first reading , these review s appear to offer different conclusions on effects on cardiovascular morbidity and regarding the benefits of supervised exercise . Either could be cited selectively to support or refute the benefits of exercise programmes for morbidity or to support or refute the incorporation of supervised exercise into services . Why might these different conclusions have come about and how should they be interpreted ? Firstly , it is unlikely that the different conclusions arise from differences in quality as both review s were of high quality as defined by PRISMA criteria and included many of the same trials : 37 of the 48 ( 77 % ) exercise-based trials were included in the 63 ( 59 % ) secondary prevention trials . Rather , issues of statistical power can explain the differences noted in morbidity . The forest plot analyses showed that , although exercise-based programmes in the Cochrane review did not reach statistically significant headline ‘ effect sizes ’ , there was a tendency towards reduced recurrent myocardial infa rct ion and the need for repeat coronary revascularization . The larger review of secondary prevention programmes considered over twice the number of events in the analysis of recurrent myocardial infa rct ion and found that secondary prevention programmes significantly reduced the rate of recurrent heart attacks . Hence , focusing only on the presence or absence of Predictors of perioperative complications , including cardiac death , ventricular tachycardia or fibrillation , and heart failure or myocardial infa rct ion , were assessed in an initial study of 100 patients aged 65 years or older scheduled for elective abdominal or noncardiac thoracic surgery .  Preoperative history , results of physical examination , chest roentgenogram , electrocardiogram , laboratory data , Dripps ( American Society of Anesthesiologists ) class , and Goldman cardiac risk index were compared with rest and exercise radionuclide ventriculograms . Thirteen patients had perioperative cardiac complications , and 6 died . Multivariate analysis showed that an inability to do 2 minutes of bicycle exercise in the supine position to raise the heart rate above 99 beats/min ( sensitivity 85 % , specificity 64 % ) gave predictive information not available from clinical or radionuclide data . On prospect i ve testing involving 55 additional geriatric patients , inability to exercise was the only independent predictor of perioperative complications ( p less than 0.05 ) . Data from rest and exercise radionuclide ventriculography added little information for predicting perioperative cardiac risk Nitrous oxide ( N2O ) has been implicated as a cause of  myocardial ischemia  . We investigated whether substitution of N2O for a portion of the anesthesia supplied by isoflurane increased myocardial ischemia in patients at risk for such ischemia . Seventy patients having carotid endarterectomies ( 63 patients ) or other carotid surgery ( seven patients ) were prospect ively , r and omly assigned to an anesthetic regimen that included or excluded N2O . All other aspects of anesthetic management were similar , except for greater concentrations of oxygen and isoflurane in patients not given N2O . Perioperative monitoring for myocardial ischemia and infa rct ion included 12− or 5-lead electrocardiography , transesophageal echocardiography , and creatine kinase isoenzyme levels . By transesophageal echocardiographic or electrocardiographic criteria , 44 % of patients given oxygen but only 21 % of those given N2O  had myocardial ischemia intraoperatively ( P = 0.065 ) . Similarly , myocardial infa rct ion , identified by changes in creatine kinase isoenzymes , occurred in only one patient given N2O but in three given oxygen ( not significantly different ) . Thus we found no trend indicating a greater incidence of myocardial ischemia or infa rct ion associated with the use of N2O BACKGROUND Cardiovascular complications are the most important causes of perioperative morbidity and mortality among patients undergoing major vascular surgery . METHODS We performed a r and omized , multicenter trial to assess the effect of perioperative blockade of beta-adrenergic receptors on the incidence of death from cardiac causes and nonfatal myocardial infa rct ion within 30 days after major vascular surgery in patients at high risk for these events . High-risk patients were identified by the presence of both clinical risk factors and positive results on dobutamine echocardiography . Eligible patients were r and omly assigned to receive st and ard perioperative care or st and ard care plus perioperative beta-blockade with bisoprolol . RESULTS A total of 1351 patients were screened , and 846 were found to have one or more cardiac risk factors . Of these 846 patients , 173 had positive results on dobutamine echocardiography . Fifty-nine patients were r and omly assigned to receive bisoprolol , and 53 to receive st and ard care .  Fifty-three patients were excluded from r and omization because they were already taking a beta-blocker , and eight were excluded because they had extensive wall-motion abnormalities either at rest or during stress testing . Two patients in the bisoprolol group died of cardiac causes ( 3.4 percent ) , as compared with nine patients in the st and ard-care group ( 17 percent , P=0.02 ) . Nonfatal myocardial infa rct ion occurred in nine patients given st and ard care only ( 17 percent ) and in none of those given st and ard care plus bisoprolol ( P<0.001 ) . Thus , the primary study end point of death from cardiac causes or nonfatal myocardial infa rct ion occurred in 2 patients in the bisoprolol group ( 3.4 percent ) and 18 patients in the st and ard-care group ( 34 percent , P<0.001 ) . CONCLUSIONS Bisoprolol reduces the perioperative incidence of death from cardiac causes and nonfatal myocardial infa rct ion in high-risk patients who are undergoing major vascular surgery PURPOSE Although early death from perioperative myocardial infa rct ion ( PMI ) after vascular surgery is well established , long-term outcome in patients surviving PMI is unknown . This prospect i ve study was design ed to determine cardiac outcome and survival rates in patients with symptomatic and asymptomatic nonfatal PMI associated with peripheral vascular surgery . METHODS During a 36-month period for 1989 to 1992 , all patients undergoing vascular surgery at our institution were monitored for PMI with serial creatine kinase and myocardial b and isoenzymes and electrocardiography . PMIs were classified as symptomatic ( associated with chest pain , arrhythmia , congestive heart failure , or hypotension ) or asymptomatic ( electrocardiographic changes and /or elevated creatine kinase and myocardial b and isoenzymes ) . Patients with PMI were then prospect ively monitored and compared for late survival , with control patients undergoing vascular surgery without PMI during the same interval . RESULTS During the study period 1561 major peripheral vascular procedures were performed . There were 47 PMIs ( 3.0 % ) . Eleven ( 0.7 % ) PMIs were fatal , 31 were nonfatal , and five other patients with PMI died during operation of non-heart-related causes . Eight of 31 patients with nonfatal PMI had a " chemical PMI " with creatine kinase and myocardial b and isoenzyme elevation as the sole indicator of PMI . During follow-up ( mean 27.7 months ) , there was a higher incidence of both subsequent myocardial infa rct ion and coronary artery revascularization among the patients with nonfatal PMI compared with control subjects ( p < 0.05 ) ; however , survival for patients with nonfatal PMI at 1 and 4 years ( 80 % and 51 % ) did not differ from that of control patients ( 90 % and 60 % ) ( p > 0.05 ) . Patients with " chemical PMI " had similar patterns of subsequent myocardial infa rct ion and coronary intervention as control patients . CONCLUSIONS Patients surviving nonfatal PMI after peripheral vascular surgery have a higher incidence of subsequent adverse cardiac events and coronary artery revascularization than patients undergoing vascular surgery without PMI , but they have similar survival rates at 1 and 4 years . Patients in the enzyme-only PMI group have a similar outcome compared with control subjects suggesting that a perioperative " chemical MI " may not be a significant clinical event BACKGROUND Globally there are > 200 million major surgical procedures undertaken annually , and about 20 % of these involve patients who have coronary artery disease . Many receive nitrous oxide , which impairs methionine synthase , thus inhibiting folate synthesis and increasing postoperative homocysteine levels . Nitrous oxide anesthesia leads to postoperative endothelial dysfunction , and there is some evidence that it increases myocardial ischemia and , possibly , myocardial infa rct ion . We have initiated the Nitrous oxide and perioperative cardiac morbidity ( ENIGMA-II ) Trial to test the hypothesis that in in patients undergoing anesthesia for major noncardiac surgery , avoidance of nitrous oxide will reduce the incidence of death and major cardiovascular events . METHODS ENIGMA-II is a 7,000-patient , international r and omized trial involving patients at risk of coronary artery disease undergoing noncardiac surgery . The patients , health care providers ( except for the anesthesiologists ) , data collectors , and outcome adjudicators are blinded to whether patients receive nitrous oxide-containing or nitrous oxide-free anesthetic . The primary outcome is a composite of death and major nonfatal events ( ie , myocardial infa rct ion , cardiac arrest , pulmonary embolism , and stroke ) at 30 days after surgery . RESULTS At present , ENIGMA-II has r and omized > 1,000 patients in 22 hospitals in 5 countries . To date , patients ' mean age is 70 years , 66 % are men , 38 % have a history of coronary artery disease , 19 % have a history of cerebrovascular disease , and 84 % have a history of hypertension . Most patients have undergone intra-abdominal 28 % , vascular 32 % , and orthopedic 16 % surgery . CONCLUSIONS The ENIGMA-II Trial will be the largest study yet conducted to ascertain the benefits and risks of removing nitrous oxide from the gas mixture in anesthesia . The results of this large international trial will guide the clinical care of the hundreds of millions of adults undergoing noncardiac surgery annually Background Smoking cessation decreases the risk for myocardial infa rct ion among people without previous coronary disease , but its effect on risk reduction after a first myocardial infa rct ion has not been well studied . Contribution The research ers retrospectively observed relative risk for recurrent coronary events in patients discharged from the hospital after an incident myocardial infa rct ion . Compared to nonsmokers , active smokers were 1.5 times more likely to have reinfa rct ion . Among persons who had stopped smoking , relative risk decreased gradually to the nonsmokers ' level over 36 months . Implication s Physicians should emphasize the proven benefits of smoking cessation to encourage patients to quit after a first myocardial infa rct ion . The Editors Smoking is a risk factor for coronary artery disease ( 1 ) . Among persons without coronary disease who quit smoking , the risk for incident coronary disease decreases and approaches that of nonsmokers within 2 to 3 years after cessation ( 2 , 3 ) . Some studies ( 4 - 17 ) show that quitting smoking after myocardial infa rct ion also seems to reduce the risk for adverse outcomes , including death . However , these studies of persons with established disease generally focused on men 65 years of age or younger , had limited information about possible confounding factors , did not evaluate the time course of the potential benefits of smoking cessation , and did not compare results to those in nonsmokers . In contrast to these studies showing a benefit of smoking cessation after myocardial infa rct ion , some evidence suggests that after infa rct ion , smokers may not have an elevated risk for recurrent events compared with never-smokers , a finding termed the smoker 's paradox ( 18 - 24 ) . We examined the association between smoking status and risk for recurrent coronary events and explored the time course of potential benefits of cessation in a large population -based inception cohort of persons who survived to hospital discharge after an incident myocardial infa rct ion . Methods Setting and Participants The study setting was Group Health Cooperative ( GHC ) , a health maintenance organization with more than 500 000 enrollees , based in western Washington State . The organization 's model of health care delivery is structured so that most routine care for enrollees , including care after myocardial infa rct ion , is provided by personal primary care physicians . Group Health Cooperative employs more than 300 primary care physicians and contracts with more than 500 other physicians . Eligible patients included all GHC enrollees who survived to hospital discharge after a first myocardial infa rct ion during the period from July 1986 ( women ) or July 1989 ( men ) through December 1996 . Patients with incident myocardial infa rct ion were identified by International Classification of Diseases , 9th revision , codes from the computerized discharge abstract s of the two GHC hospitals , bills for out-of-plan services provided by non-GHC physicians and health care facilities , and Washington State death records . A trained records abstract or , assisted by study physicians , vali date d the incident infa rct ions by review ing available inpatient medical records . Previous work ( 25 ) has confirmed the accuracy and completeness of the methods used for ascertainment of myocardial infa rct ion .  Persons were excluded if they were younger than 30 or older than 79 years of age at the time of the incident infa rct ion , had previously had a myocardial infa rct ion , had the incident infa rct ion as a result of surgery or another procedure , died before hospital discharge , or had no information available in the medical record after the incident infa rct ion . A total of 50 patients ( 1.8 % of the total otherwise eligible patients ) were discharged alive from the hospital but had no information in the chart after the incident infa rct ion . Persons were also excluded if they had made fewer than four visits to GHC or had been enrolled in GHC for less than 1 year before the incident infa rct ion . Among persons otherwise eligible for inclusion , 9.3 % were excluded because of inadequate duration of enrollment in GHC . Of the 2677 patients who were initially eligible , 58 were excluded because of indeterminate smoking status , leaving 2619 persons ( 97.8 % of the original cohort ) for analysis . The Human Subjects Review Committees of GHC approved the study . Smoking Status We identified smoking status on the basis of ambulatory care and inpatient records . The GHC ambulatory medical record is an important re source because it serves as the primary method of communication among GHC physicians . It includes not only notes from ambulatory care visits but also discharge summaries of hospitalizations , results of laboratory and diagnostic tests , consultant reports , responses to annual GHC health question naires , and up date d problem lists . Data collection included a review of the entire GHC ambulatory medical record for the period before the first infa rct ion , the period of hospitalization associated with the incident infa rct ion , and the period after the infa rct ion up to a predetermined date in 1996 , 1997 , or 1998 . Patients were classified as nonsmokers ( persons with no history of smoking in the medical record ) , former smokers ( persons who had smoked but had quit before the incident myocardial infa rct ion ) , quitters ( persons who were smoking at the time of the incident myocardial infa rct ion and quit after the infa rct ion ) , and active smokers ( persons who were smoking at the time of the incident myocardial infa rct ion and continued to smoke during follow-up ) . Only those persons who quit smoking after their incident infa rct ion and maintained cessation for the duration of follow-up were classified as quitters . Information about the quit date , number of cigarettes smoked per day , and duration of smoking over time was also recorded . Patients were closely monitored after the incident infa rct ion ; 97.6 % had a clinic visit within 3 months after hospital discharge , and the median number of visits ( physician , nurse , or emergency department visits or hospitalizations ) during the first year after the incident infa rct ion was 9 ( 25th , 75th percentiles : 6 , 14 ) . Clinical and Medication Covariates Trained research assistants review ed the ambulatory care and inpatient medical records to collect information about potential risk factors for coronary disease , such as use of health services ; marital status ; alcohol consumption ; body weight ; height ; and medical conditions such as hypertension , diabetes , and congestive heart failure . Congestive heart failure was determined to have occurred on the basis of the notes of the primary care physician and consultants and the results of diagnostic tests . Hypertension was defined as pharmacologically treated hypertension ; diabetes was defined as diabetes pharmacologically treated with oral hypoglycemic agents or insulin . In addition , laboratory values for r and om serum glucose , total cholesterol , and high-density lipoprotein cholesterol were recorded . Medication use was assessed at the time of hospital discharge after the incident infa rct ion by using information from the discharge summary supplemented with information from the first outpatient visit and the GHC computerized pharmacy data base . The status of the clinical and medication covariates was determined at the time of hospital discharge . Laboratory information was taken from the period before the incident infa rct ion . End Point The outcome of interest was recurrent coronary events , defined as nonfatal myocardial infa rct ion or coronary death . Information on these end points was obtained from the GHC ambulatory medical record , available inpatient records , and the results of matches between Washington State death records and GHC enrollment records . In patients with established coronary disease , if the underlying cause of death was heart disease , heart failure , or arrhythmia , the death was classified as a coronary death . Statistical Analysis Follow-up time began at the date of discharge from the hospital after the incident infa rct ion , and it extended to the date of the first recurrent infa rct ion , coronary death , or censoring . Persons were censored at the date of death from causes other than heart disease , the date of unenrollment from GHC , or the end of the assigned follow-up period . Cox proportional-hazards regression analysis with a time-dependent smoking status variable was used to model the association of smoking status and recurrent coronary events after adjustment for potential confounding factors ( 26 ) . A patient who quit smoking during hospitalization for the incident myocardial infa rct ion was classified as a quitter . For those who quit smoking after discharge , smoking status was modeled with person-years accrued initially as if the patient were an active smoker and then after cessation as if the patient were a quitter . To investigate the risk for recurrent coronary events in relation to the duration of smoking cessation , we divided follow-up time into four mutually exclusive categories of duration of cessation ( 0 to < 6 months , 6 to < 18 months , 18 to < 36 months , and 36 months ) . Because the underlying time scale used in the regression analysis was time since hospital discharge after the first myocardial infa rct ion , the Cox model adjusts for time since infa rct ion , enabling an assessment of the relationship of duration of cessation independent of time since infa rct ion . In addition , because most patients who quit smoking did so very soon after the incident infa rct ion , time since hospital discharge and time since cessation of smoking were similar for many quitters . To help discern whether the change seen among quitters in the hazard ratio over time was due to smoking cessation rather than to any other characteristic of smokers that changed over time after discharge , we also evaluated whether the coronary event hazard ratio among active smokers varied with time since infa rct ion . We calculated the unadjusted rates of recurrent OBJECTIVE To determine whether patterns of facial expressions of patients complaining of chest pain can aid in the diagnosis of myocardial infa rct ions . DESIGN Exploratory . SETTING Southeastern university medical center emergency department ( ED ) . PATIENTS Twenty-eight patients in the ED who presented with chest pain . Age range was 40 to 84 years , with a mean of 65.4 years . OUTCOME MEASURES Common patterns of facial expressions among patients diagnosed with myocardial infa rct ion . INTERVENTION On admission to the ED , patients were videotaped during physical examination . Videotapes were review ed to code the facial action units exhibited by the patients . The presence or absence of creatine kinase ( CK ) enzymes was determined ; these results were blinded to the coders until after all facial actions were coded . RESULTS With use of the Facial Action Coding System , 4 facial expressions were found to be associated with true myocardial infa rct ion : lowering the brow , pressing the lips , parting the lips , and turning the head left . CONCLUSION Additional research with a larger sample of patients presenting with chest pain is needed to vali date the findings of this study . However , if these findings are supported , instruction regarding assessment of specific facial expressions in clinical setting s may be warranted Background : High-sensitivity troponin assays are now available for clinical use . We investigated whether early measurement with such an assay is superior to a conventional assay in the evaluation of acute coronary syndromes . Methods : Patients presenting to an emergency department with chest pain who did not have ST-segment elevation were prospect ively recruited from November 2007 to December 2010 . Patients underwent serial testing with a conventional cardiac troponin I assay . Sample s were also obtained at presentation and two hours later for measurement of troponin T levels using a high-sensitivity assay . The primary outcome was diagnosis of myocardial infa rct ion on admission ; secondary outcomes were death , myocardial infa rct ion and heart failure at one year . Results : Of the 939 patients enrolled in the study , 205 ( 21.8 % ) had myocardial infa rct ion . By two hours after presentation , the high-sensitivity troponin T assay at the cut-off point of the 99th percentile of the general population ( 14 ng/L ) had a sensitivity of 92.2 % ( 95 % confidence interval [ CI ] 88.1%–95.0 % ) and a specificity of 79.7 % ( 95 % CI 78.6%–80.5 % ) for the diagnosis of non – ST-segment myocardial infa rct ion . The sensitivity of the assay at presentation was 100 % among patients who presented four to six hours after symptom onset . By one year , the high-sensitivity troponin T assay was found to be superior than the conventional assay in predicting death ( hazard ratio [ HR ] 5.4 , 95 % CI 2.7–10.7 ) and heart failure ( HR 27.8 , 95 % CI 6.6–116.4 ) , whereas the conventional assay was superior in predicting nonfatal myocardial infa rct ion ( HR 4.0 , 95 % CI 2.4–6.7 ) . Interpretation : The high-sensitivity troponin T assay at the cut-off point of the 99th percentile was highly sensitive for the diagnosis of myocardial infa rct ion by two hours after presentation and had prognostic utility beyond that of the conventional assay . To rule out myocardial infa rct ion , the optimal time to test a second sample using the high-sensitivity troponin T level may be four to six hours after symptom onset , but this finding needs verification in future studies before it can become routine practice BACKGROUND : There is a plausible pathophysiologic rationale for increased long-term cardiovascular morbidity and mortality in patients receiving significant exposure to nitrous oxide .  However , this relationship has not been established clinical ly . The ENIGMA trial r and omized 2050 patients having noncardiac surgery lasting more than 2 hours to nitrous oxide – based or nitrous oxide – free anesthesia .  We conducted a follow-up study of the ENIGMA patients to evaluate the risk of cardiovascular events in the longer term . METHODS : The trial case report forms and medical records of all study patients were review ed . The date and cause of death and occurrence of myocardial infa rct ion or stroke were recorded . A telephone interview was then conducted with all surviving patients . The primary endpoint of the study was survival . RESULTS : The median follow-up time was 3.5 ( range : 0 to 5.7 ) years . Three hundred eighty patients ( 19 % ) had died since the index surgery , 91 ( 4.5 % ) were recorded as having myocardial infa rct ion , and 44 ( 2.2 % ) had a stroke during the entire follow-up period . Nitrous oxide did not significantly increase the risk of death [ hazard ratio = 0.98 ( 95 % confidence interval , CI : 0.80 to 1.20 ; P = 0.82 ) ] . The adjusted odds ratio for myocardial infa rct ion in patients administered nitrous oxide was 1.59 ( 95 % CI : 1.01 to 2.51 ; P = 0.04 ) and for stroke was 1.01 ( 95 % CI : 0.55 to 1.87 ; P = 0.97 ) . CONCLUSIONS : The administration of nitrous oxide was associated with increased long-term risk of myocardial infa rct ion , but not of death or stroke in patients enrolled in the ENIGMA trial . The exact relationship between nitrous oxide administration and serious long-term adverse outcomes will require confirmation by an appropriately design ed large r and omized controlled trial In a double-blind trial comparing two thrombolytic agents as treatment for acute myocardial infa rct ion , we r and omized 270 consecutive patients an average ( + /- SD ) of 2.5 + /- 0.6 hours after the onset of chest pain from a first myocardial infa rct ion--135 to receive intravenous streptokinase ( 1.5 million units over 30 minutes ) and 135 to receive intravenous recombinant tissue plasminogen activator ( rt-PA ) ( 100 mg over three hours ) . The primary end point was left ventricular function as assessed by cineangiography performed three weeks after infa rct ion . The effects of the two agents on left ventricular function were similar . The ejection fraction was identical ( 58 + /- 12 percent ) in both groups . The end-systolic volume was 61 + /- 29 ml in the streptokinase group and 66 + /- 31 ml in the rt-PA group ( P not significant ) . Patency rates at three weeks for the infa rct -related artery were also similar ( 75 percent in the streptokinase group and 76 percent in the rt-PA group ) . Reinfa rct ion rates at 30 days were the same ( 5 percent ) in both groups . One patient had a fatal intracerebral hemorrhage 13 hours after receiving rt-PA , and another had a fatal cerebellar hemorrhage 21 hours after receiving rt-PA for reinfa rct ion nine days after treatment with streptokinase . An intention-to-treat analysis revealed that mortality at 30 days was 3.7 percent in the rt-PA group as compared with 7.4 percent in the streptokinase group ( P greater than 0.2 ) . Follow-up for a mean of 9.0 months revealed no significant difference in survival ; we observed 12 deaths ( 8.9 percent ) in the streptokinase group and 8 deaths ( 5.9 percent ) in the rt-PA group ( P = 0.34 ) . We conclude that rt-PA and streptokinase , in the doses given , have similar effects on left ventricular function after a first myocardial infa rct ion . Because of the small number of deaths , it is not possible to determine whether their effects on mortality are similar STUDY OBJECTIVE The present study was performed to determine the influence of a perioperative myocardial infa rct ion on long-term mortality in patients who have undergone elective vascular surgery .  STUDY DESIGN This was a 4-year follow-up of patients who had undergone elective vascular procedures at a Veterans Affairs Medical Center . Between January 1989 and December 1990 , 115 consecutive patients underwent surgery for either an exp and ing abdominal aortic aneurysm ( AAA ) ( 38 % ) or for pain in the lower extremities ( 62 % ) . RESULTS Vital status at 4 years postsurgery was determined for all patients . Thirty-day postoperative mortality was 3 % , while estimates at 1 , 2 , 3 , and 4 years were 19 % , 26 % , 35 % , and 39 % , respectively . Of the 45 patients who died within 4 years following surgery , the major causes of death were cardiac ( 40 % ) , cancer ( 18 % ) , cerebrovascular ( 13 % ) , and peripheral vascular disease ( 11 % ) . Univariate predictors of 1-year mortality on preoperative evaluation were an abnormal ECG , moderate or greater sized exercise thallium defect and left ventricular ejection fraction < or = 40 % , and a perioperative myocardial infa rct ion . Univariate predictors of 4-year mortality were non-AAA surgery and diabetes mellitus . Perioperative myocardial infa rct ion was a marginally significant independent predictor of 1-year mortality ( p=0.06 ) , while the need for non-AAA surgery was a strong independent predictor at 4 years . CONCLUSIONS Cardiac mortality is the major cause of late death among patients undergoing elective vascular surgery . Although preoperative indicators of symptomatic coronary artery disease and nonfatal perioperative myocardial infa rct ion identified those individuals at increased mortality in the first postoperative year , the extent of vascular disease at presentation may be a more important determinant of long-term survival . A r and omized trial in such patients is needed to assess the best strategy for treating patients with coexistent coronary artery and vascular diseases BACKGROUND The implantable cardioverter/defibrillator ( ICD ) has been shown to be superior to antiarrhythmic drug therapy for the secondary prevention of sudden cardiac death . Its role in the primary prevention of sudden death after myocardial infa rct ion is unknown . Methods and Results The Defibrillator in Acute Myocardial Infa rct ion Trial ( DINAMIT ) is a r and omized , open-label , parallel-group comparison of ICD therapy versus no ICD therapy in selected survivors of acute myocardial infa rct ion . It will test the hypothesis that reduction of sudden arrhythmogenic death by means of the ICD will result in reduction of overall mortality rates in patients at high risk after acute myocardial infa rct ion . Accordingly , this international multicenter study aims to enroll patients shortly after their infa rct ion ( day 6 to day 40 ) who have reduced left ventricular function ( left ventricular ejection fraction < /=0 . 35 ) and impairment of cardiac autonomic function shown by depressed heart rate variability ( st and ard deviation of normal-to-normal R-R intervals < /=70 ms ) or elevated average 24-hour heart rate ( mean 24-hour R-R interval < /=750 ms , assessed by Holter monitoring ) . Patients will be followed for approximately 3 years on average with subsequent data analysis based on the intent-to-treat principle . Primary outcome is all-cause death . The trial is expected to be completed in 2003 . CONCLUSIONS DINAMIT is the first prospect i ve study to evaluate the benefit of ICD therapy for the primary prevention of sudden cardiac death in patients at high risk after acute myocardial infa rct ion BACKGROUND Although previous investigations have suggested that 24 hours is required to exclude acute myocardial infa rct ion in patients who are admitted to a coronary care unit for the evaluation of acute chest pain , we hypothesized that a 12-hour period might be adequate for patients with a low probability of infa rct ion at the time of admission . METHODS Using a Bayesian model , we developed a strategy to identify c and i date s for a shorter period of observation from an analysis of a derivation set of 976 patients with acute chest pain who were admitted to three teaching and four community hospitals . In the derivation set , patients whose clinical characteristics in the emergency room predicted a low ( less than or equal to 7 percent ) probability of myocardial infa rct ion had only a 0.4 percent risk of infa rct ion if they had neither abnormal levels of cardiac enzymes nor recurrent ischemic pain during the first 12 hours of hospitalization . In an independent testing set of 2684 patients from the seven hospitals , 957 admitted patients ( 36 percent ) were classified as c and i date s for this 12-hour period of observation according to a previously published multivariate algorithm . Few of these patients were actually transferred from a monitored setting at 12 hours . RESULTS Of the 771 c and i date s for a 12-hour period of observation who did not have enzyme abnormalities or recurrent pain during the first 12 hours , 4 ( 0.5 percent ) were subsequently found to have acute myocardial infa rct ion , and only 3 ( 0.4 percent ) died after primary cardiac arrests , all of which occurred three to five days after admission . Rates of other major cardiovascular complications were low in the patients who might have been transferred from the coronary care unit after 12 hours with this strategy . In patients with a higher initial risk of infa rct ion , the st and ard strategy of 24-hour observation identified all but 11 of 739 acute myocardial infa rct ions ( 1 percent ) . CONCLUSIONS Emergency room clinical data can be used to identify a large subgroup of patients for whom a 12-hour period of observation is normally sufficient to exclude acute myocardial infa rct ion . Patient-specific evaluation and treatment can then proceed without the restrictions imposed by " rule-out " protocol s for myocardial infa rct ion Background and objectives Peroperative myocardial infa rct ion ( MI ) is the most common cause of morbidity and mortality . What is the role of general anesthesia in this process ? Is general anesthesia a risk for myocardial infa rct ion ? The present study was design ed to determine whether the measurement of serum levels of cardiac troponin I ( cTnI ) , a highly sensitive and specific marker for cardiac injury , would help establish the diagnosis of myocardial infa rct ion in two different types of anesthesia . Method Elective abdominal hysterectomy  was planned with the permission of the ethic committee in 40 patients who were 20–45 years range , in ASA-I group , and have a Goldman Cardiac Risk Index-0 . The patients were divided into two groups . Isoflurane + N2O was administrated to first group , and Propofol + Fentanyl to second group .  cTnI levels were determined before anesthesia , after induction before surgery and 9 hours after the second period respectively . Results There was no significant difference between the groups by the means of demographic properties , hemodynamic parameters and cTnI levels , and the cTnI levels were determined under the basal levels in all sample s. Conclusion General anesthesia is not a risk for myocardial infa rct ion to state eliminating risk factors and protection hemodynamia cardiac BACKGROUND This post hoc analysis aim ed to determine whether neuraxial block was associated with a composite of cardiovascular death , non-fatal myocardial infa rct ion ( MI ) and non-fatal cardiac arrest within 30 days of r and omization in POISE trial patients . METHODS A total of 8351 non-cardiac surgical patients at high risk of cardiovascular complications were r and omized  to β-blocker or placebo . Neuraxial block was defined as spinal , lumbar or thoracic epidural anaesthesia . Logistic regression , with weighting using estimated propensity scores , was used to determine the association between neuraxial block and primary and secondary outcomes . RESULTS Neuraxial block was associated with an increased risk of the primary outcome [ 287 ( 7.3 % ) vs 229 ( 5.7 % ) ; odds ratio ( OR ) , 1.24 ; 95 % confidence interval ( CI ) , 1.02 - 1.49 ; P=0.03 ] and MI [ 230 ( 5.9 % ) vs 177 ( 4.4 % ) ; OR , 1.32 ; 95 % CI , 1.07 - 1.64 ; P=0.009 ] but not stroke [ 23 ( 0.6 % ) vs 32 ( 0.8 % ) ; OR , 0.76 ; 95 % CI , 0.44 - 1.33 ; P=0.34 ] , death [ 96 ( 2.5 % ) vs 111 ( 2.8 % ) ; OR , 0.87 ; 95 % CI , 0.65 - 1.17 ; P=0.37 ] or clinical ly significant hypotension [ 522 ( 13.4 % ) vs 484 ( 12.1 % ) ; OR , 1.13 ; 95 % CI , 0.99 - 1.30 ; P=0.08 ] . Thoracic epidural with general anaesthesia was associated with a worse primary outcome than general anaesthesia alone [ 86 ( 12.1 % ) vs 119 ( 5.4 % ) ; OR , 2.95 ; 95 % CI , 2.00 - 4.35 ; P<0.001 ] . CONCLUSIONS In patients at high risk of cardiovascular morbidity , neuraxial block was associated with an increased risk of adverse cardiovascular outcomes , which could be causal or because of residual confounding Objective To determine the effect of calcium supplementation on myocardial infa rct ion , stroke , and sudden death in healthy postmenopausal women . Design R and omised , placebo controlled trial . Setting Academic medical centre in an urban setting in New Zeal and . Participants 1471 postmenopausal women ( mean age 74 ) : 732 were r and omised to calcium supplementation and 739 to placebo .  Main outcome measures Adverse cardiovascular events over five years : death , sudden death , myocardial infa rct ion , angina , other chest pain , stroke , transient ischaemic attack , and a composite end point of myocardial infa rct ion , stroke , or sudden death . Results Myocardial infa rct ion was more commonly reported in the calcium group than in the placebo group ( 45 events in 31 women v 19 events in 14 women , P=0.01 ) . The composite end point of myocardial infa rct ion , stroke , or sudden death was also more common in the calcium group ( 101 events in 69 women v 54 events in 42 women , P=0.008 ) . After adjudication myocardial infa rct ion remained more common in the calcium group ( 24 events in 21 women v 10 events in 10 women , relative risk 2.12 , 95 % confidence interval 1.01 to 4.47 ) . For the composite end point 61 events were verified in 51 women in the calcium group and 36 events in 35 women in the placebo group ( relative risk 1.47 , 0.97 to 2.23 ) . When unreported events were added from the national data base of hospital admissions in New Zeal and the relative risk of myocardial infa rct ion was 1.49 ( 0.86 to 2.57 ) and that of the composite end point was 1.21 ( 0.84 to 1.74 ) . The respective rate ratios were 1.67 ( 95 % confidence intervals 0.98 to 2.87 ) and 1.43 ( 1.01 to 2.04 ) ; event rates : placebo 16.3/1000 person years , calcium 23.3/1000 person years . For stroke ( including unreported events ) the relative risk was 1.37 ( 0.83 to 2.28 ) and the rate ratio was 1.45 ( 0.88 to 2.49 ) . Conclusion Calcium  supplementation in healthy postmenopausal women is associated with upward trends in cardiovascular event rates . This potentially detrimental effect should be balanced against the likely benefits of calcium on bone . Trial registration Australian Clinical Trials Registry ACTRN 012605000242628 BACKGROUND Artificial neural networks apply non-linear statistics to pattern recognition problems . One such problem is acute myocardial infa rct ion ( AMI ) , a diagnosis which , in a patient presenting as an emergency , can be difficult to confirm . We report here a prospect i ve comparison of the diagnostic accuracy of a network and that of physicians , on the same patients with suspected AMI . METHODS Emergency department physicians who evaluated 1070 patients 18 years or older presenting to the emergency department of a teaching hospital in California , USA with anterior chest pain indicated whether they thought these patients had sustained a myocardial infa rct ion . The network analysed the patient data collected by the physicians during their evaluations and also generated a diagnosis . FINDINGS The physicians had a diagnostic sensitivity and specificity for myocardial infa rct ion of 73.3 % ( 95 % confidence interval 63.3 - 83.3 % ) and 81.1 % ( 78.7 - 83.5 % ) , respectively , while the network had a diagnostic sensitivity and specificity of 96.0 % ( 91.2 - 100 % ) and 96.0 % ( 94.8 - 97.2 % ) , respectively . Only 7 % of patients had had an AMI , a low frequency but typical for anterior chest pain . INTERPRETATION The application of non-linear neural computational analysis via an artificial neural network to the clinical diagnosis of myocardial infa rct ion appears to have significant potential BACKGROUND Before any new diagnostic test is accepted in clinical practice , such a test should be compared with established diagnostic tools in an appropriately large series of patients encompassing the complete spectrum of challenges to which the test is exposed . The aim of the present study was to assess the relative diagnostic and prognostic accuracies of high-dose dipyridamole echocardiography ( two-dimensional echocardiographic monitoring during dipyridamole infusion up to 0.84 mg/kg over 10 hours ) versus maximal symptom-limited bicycle exercise ECG test in patients with angina . METHODS AND RESULTS We studied 429 consecutive in-hospital patients who met the following inclusion criteria : history of chest pain , off antianginal therapy for at least 2 days ( 1 week for beta-blockers ) , no previous myocardial infa rct ion and /or obvious regional left ventricular dyssynergy of contraction ( akinesis or dyskinesis ) at baseline , and acceptable acoustic window under resting conditions . All patients underwent dipyridamole echocardiography and exercise ECG -- on different days and in r and om order -- within 1 week of coronary angiography ( which was performed independent of test results ) and were followed up for 37.8 + /- 14 months ( range , 1 to 73 months ) . Criteria of positivity were for dipyridamole echocardiography , a transient regional dyssynergy absent in the baseline examination ; for exercise ECG , an ST-segment shift of > or = 0.1 mV from baseline ; and for coronary angiography , a luminal reduction of > or = 75 % in at least one major coronary vessel ( 50 % for left main ) . There were 183 patients without and 246 with coronary artery disease ; 132 had one- , 70 had two- , and 44 had three- and /or left main vessel disease . The specificity was higher for dipyridamole echocardiography than for exercise ECG ( 90 % versus 51 % , P < .001 ) . The overall sensitivity of dipyridamole echocardiography  was similar to that of  exercise ECG  ( 75 % versus 74 % , P = NS ) , with no significant differences in the subset with one- ( 67 % versus 69 % , P = NS ) , two- ( 79 % versus 77 % , P = NS ) , or three- ( 93 % versus 86 % , P = NS ) vessel disease . During the follow-up , there were 20 deaths , 13 nonfatal myocardial infa rct ions , and 126 revascularization procedures . In the univariate analysis , dipyridamole result ed in higher chi 2 values than did exercise stress testing . A Cox forward stepwise survival analysis identified the  dipyridamole time as the most powerful prognostic predictor of death ( chi 2 = 19.4 , P < .0001 ) of all invasive and noninvasive parameters . The dipyridamole time also provided independent and additional prognostic information when it was adjusted for age , diabetes , resting ECG , and exercise stress test according to a modified , interactive stepwise procedure . This is true when death only , death and myocardial infa rct ion , and death , myocardial infa rct ion , and revascularization procedures were considered end points . CONCLUSIONS In patients with no previous myocardial infa rct ion and good resting left ventricular function , compared with exercise ECG , dipyridamole echocardiography has a similar sensitivity and a higher specificity for the noninvasive detection of angiographically assessed coronary artery disease . Dipyridamole echocardiography also provides information in addition to that provided by exercise ECG for predicting death , infa rct ion , and all events when the presence as well as the timing , severity , and extension of  dipyridamole-induced wall motion abnormalities are considered BACKGROUND Glycoprotein IIb/IIIa blockers reduce procedure-related thrombotic complications of percutaneous coronary intervention , and the risk of death and myocardial infa rct ion in patients with acute coronary syndromes . The effect on risk of death and myocardial infa rct ion is particularly apparent in patients undergoing early percutaneous coronary interventions . We did a r and omised , multicentre trial to study the effect of the glycoprotein IIb/IIIa blocker abciximab on patients with acute coronary syndromes who were not undergoing early revascularisation . METHODS We enrolled 7800 patients who were admitted to hospital with chest pain and either ST-segment depression or raised troponin T or I concentrations . 2598 were r and omly assigned placebo , 2590 an abciximab bolus and 24 h infusion , and 2612 an abciximab bolus and 48 h infusion ; all patients received aspirin and either unfractionated or low-molecular-weight heparin . The primary endpoint was death or myocardial infa rct ion at 30 days after r and omisation . Analysis was by intention to treat . FINDINGS There were no drop-outs . 209 ( 8.0 % ) patients on placebo , 212 ( 8.2 % ) on 24 h abciximab , and 238 ( 9.1 % ) on 48 h abciximab  died or had a myocardial infa rct ion before day 30 ( odds ratio 1.0 [ 95 % CI 0.83 - 1.24 ] , for difference between placebo and 24 h abciximab , and 1.1 [ 0.94 - 1.39 ] for difference between placebo and 48 h abciximab ) . The lack of benefit from treatment with abciximab was consistent in most subgroups investigated ; in particular , no benefit was seen in patients with raised cardiac troponin T or I concentrations at enrolment , although these patients did have a strongly increased risk of subsequent events . Bleeding rates were low , but increased with abciximab , particularly when continued for 48 h. Additionally , thrombocytopenia was more frequent with abciximab than with placebo . INTERPRETATIONS Although the explanations for our findings are unclear , this study indicates that abciximab is not beneficial as first-line medical treatment in patients admitted with acute coronary syndromes CONTEXT Elderly persons and women were underrepresented in r and omized controlled trials ( RCTs ) prior to 1990 . Since then , efforts have been made to correct these biases , but their effect is unclear . OBJECTIVE To determine whether the percentage of elderly persons and women in published clinical trials of acute coronary syndromes has increased and how this enrollment compared with disease prevalence . DATA SOURCES The MEDLINE and Cochrane data bases were search ed for English- language articles from January 1966 to March 2000 regarding myocardial infa rct ion , unstable angina , or acute coronary syndromes . Additional data sources included meta-analyses , review articles , and cardiology textbooks . Estimates of community-based myocardial infa rct ion rates came from the National Registry of Myocardial Infa rct ion and the Worcester Heart Study . STUDY SELECTION Published RCTs of acute coronary syndrome patients were included and trials enrolling 50 patients or fewer , those without clinical end points , papers published in a language other than English , and unpublished manuscripts were excluded . Of 7645 studies identified , 593 RCTs were selected for review . DATA EXTRACTION The RCTs were abstract ed by 2 of the authors for year of publication , source of support ( ie , funding ) , pharmacotherapy , study phase , number of study sites , trial location , number of patients , mean age of the study population , and any age exclusion criteria for enrollment . DATA SYNTHESIS The number of published RCTs with explicit age exclusions has declined from 58 % during 1966 - 1990 to 40 % during 1991 - 2000 . Trial enrollment of patients aged 75 years or older increased from 2 % for studies published during 1966 - 1990 to 9 % during 1991 - 2000 , but remains well below their representation among all patients with myocardial infa rct ion ( 37 % ) in the United States . Enrollment of women has risen from 20 % for studies published between 1966 - 1990 to 25 % during 1991 - 2000 , but remains well below their proportion of all patients with myocardial infa rct ion ( 43 % ) in the United States . CONCLUSIONS Attempts at making cardiovascular RCTs more inclusive appear to have had limited success ; thus , women and elderly persons remain underrepresented in published trial literature relative to their disease prevalence . Because safety and efficacy can vary as a function of sex and age , these enrollment biases undermine efforts to provide evidence -based care to all cardiac patients OBJECTIVES Definitive evidence that red blood cell transfusion improves outcome after vascular surgery is lacking . The aims of the study were to determine , among stable consecutive patients who underwent elective major vascular surgery  , ( 1 ) the association between postoperative transfusion and 30-day death , myocardial infa rct ion , and both , and ( 2 ) and if this association differs according to the presence of postoperative anaemia ( haemoglobin value less than 9.0 g/dL within 7 days after surgery ) . METHODS A retrospective observational study was conducted on 359 patients prospect ively screened according to the ACC/AHA guidelines for preoperative risk in non-cardiac surgery . Main outcome was 30-day death ; secondary outcomes 30-day myocardial infa rct ion , and composite of 30-day myocardial infa rct ion or death . RESULTS Of the patients included , 95 ( 26.5 % ) received at least one unit of red blood cells . Patients who received transfusion had a significantly increased hazard of 30-day death ( hazard ratio [ HR ] 11.72 , 95 % confidence interval [ CI ] 3.92 - 35.10 ; p<0.0001 ) , myocardial infa rct ion ( HR 3.3 , 95 % CI 1.7 - 6.1 ; p=0.0003 ) , and both ( HR 4.0 95 % CI 2.2 - 7.3 ; p<0.0001 ) . Such associations held even after adjusting for baseline characteristics , surgical risk , bleeding , and propensity to receive transfusion . There was a significant interaction between transfusion and postoperative anaemia ( p=0.012 ) . In patients without anaemia , transfusion was associated with higher risk of 30-day death ( HR 19.20 , 95 % CI 3.99 - 92.45 ; p=0.007 ) , myocardial infa rct ion ( HR 5.05 , 95 % CI 2.23 - 11.44 ; p=0.0001 ) , and both . Conversely , in patients with anaemia this association was not significant . CONCLUSIONS In patients who underwent elective major vascular surgery , perioperative transfusion was associated with a significantly increased risk of 30-day events which was more attributable to patients with lesser degree of anaemia . Our data caution against the use of liberal transfusion in stable vascular surgery patients To determine the effect of beta blockade with propranolol on myocardial oxygen dem and s and postoperative arrhythmias in patients having coronary bypass operations , 50 patients with chronic stable angina undergoing operation were r and omized in a double-blind fashion to receive either propranolol ( 60 mg every 6 hours ) or a placebo . Drug administration began 24 to 48 hours prior to operation and continued through the operative period and for one month after operation . There were no deaths . Two perioperative myocardial infa rct ions occurred , both in patients receiving a placebo .  Myocardial oxygen dem and as measured by the rate-pressure product ( heart rate X mean arterial pressure ) was significantly reduced during induction of anesthesia ( 7,658 + /- 451 versus 5,786 + /- 340 ; p less than 0.002 ) and during sternotomy ( 8,400 + /- 550 versus 6,756 + /- 384 ; p less than 0.02 ) in propranolol-treated patients . In the first two postoperative days , nitroprusside was required for control of hypertension of 10 patients in the placebo group but in only 3 patients given propranolol ( p less than 0.05 ) . Postoperatively , 15 of the 26 patients who received a placebo had 45 episodes of arrhythmia . Seven of the 24 propranolol-treated patients had 17 episodes ( p less than 0.04 ) . We conclude that propranolol given perioperatively in doses large enough to induce beta blockade significantly reduces myocardial oxygen dem and s in the vulnerable period during induction of anesthesia and sternotomy , reduces the need for antihypertensive therapy in the immediate postoperative period , and causes a marked reduction in the incidence and frequency of both supraventricular and ventricular arrhythmias in the postoperative period BACKGROUND Endarterectomy benefits certain patients with carotid stenosis , but benefits are lessened by perioperative surgical risk . Acetylsalicylic acid lowers the risk of stroke in patients who have experienced transient ischaemic attack and stroke . We investigated appropriate doses and the role of acetylsalicylic acid in patients undergoing carotid endarterectomy . METHODS In a r and omised , double-blind , controlled trial , 2849 patients scheduled for endarterectomy were r and omly assigned 81 mg ( n=709 ) , 325 mg ( n=708 ) , 650 mg ( n=715 ) , or 1300 mg ( n=717 ) acetylsalicylic acid daily , started before surgery and continued for 3 months . We recorded occurrences of stroke , myocardial infa rct ion , and death . We compared patients on the two higher doses of acetylsalicylic acid with patients on the two lower doses . FINDINGS Surgery was cancelled in 45 patients , none were lost to follow-up by 30 days , and two were lost by 3 months . The combined rate of stroke , myocardial infa rct ion , and death was lower in the low-dose groups than in the high-dose groups at 30 days ( 5.4 vs 7.0 % , p=0.07 ) and at 3 months ( 6.2 vs 8.4 % , p=0.03 ) . In an efficacy analysis , which excluded patients taking 650 mg or more acetylsalicylic acid before r and omisation , and patients r and omised within 1 day of surgery , combined rates were 3.7 % and 8.2 % , respectively , at 30 days ( p=0.002 ) and 4.2 % and 10.0 % at 3 months ( p=0.0002 ) . INTERPRETATION The risk of stroke , myocardial infa rct ion , and death within 30 days and 3 months of endarterectomy is lower for patients taking 81 mg or 325 mg acetylsalicylic acid daily than for those taking 650 mg or 1300 mg
: Compared with general anesthesia , neuraxial anesthesia may reduce the 0-to-30-day mortality for patients undergoing a surgery with an intermediate-to-high cardiac risk ( level of evidence moderate ) .
BACKGROUND : This analysis summarized Cochrane review s that assess the effects of neuraxial anesthesia on perioperative rates of death , chest infections , and myocardial infa rct ion .