Clinical Factors That May Influence the Choice of Revascularization 3.9.1. Diabetes Mellitus An analysis performed in 2009 of data on 7812 patients (1233 with diabetes) in 10 RCTs demonstrated a worse long-term survival rate in patients with diabetes mellitus after balloon angioplasty or BMS implantation than after CABG.451 The BARI 2D trial404 randomly assigned 2368 patients with type 2 diabetes and CAD to undergo intensive medical therapy or prompt revascularization with PCI or CABG, according to whichever was thought to be more appropriate. By study design, those with less extensive CAD more often received PCI, whereas those with more extensive CAD were more likely to be treated with CABG. The study was not designed to compare PCI with CABG. At 5-year follow-up, no differ- ence in rates of survival or MACE between the medical therapy group and those treated with revascularization was noted. In the PCI stratum, no significant difference in MACE between medical therapy and revascularization was demon- strated (DES in 35%; BMS in 56%); in the CABG stratum, MACE occurred less often in the revascularization group. One-year follow-up data from the SYNTAX study demon- strated a higher rate of repeat revascularization in patients with diabetes mellitus treated with PCI than with CABG, driven by a tendency for higher repeat revascularization rates in those with higher SYNTAX scores undergoing PCI.364 In summary, in subjects requiring revascularization for multi- vessel CAD, current evidence supports diabetes mellitus as an important factor when deciding on a revascularization strat- egy, particularly when complex or extensive CAD is present (Figure 2). See Online Data Supplements 21 and 22 for additional data regarding diabetes mellitus. 3.9.2. Chronic Kidney Disease Cardiovascular morbidity and mortality rates are markedly increased in patients with chronic kidney disease (CKD) when compared with age-matched controls without CKD.


Chronic Kidney Disease Cardiovascular morbidity and mortality rates are markedly increased in patients with chronic kidney disease (CKD) when compared with age-matched controls without CKD. The mortality rate for patients on hemodialysis is 20% per year, and approximately 50% of deaths among these patients are due to a cardiovascular cause.476,477 To date, randomized comparisons of coronary revascular- ization (with CABG or PCI) and medical therapy in patients with CKD have not been reported. Some, but not all, observational studies or subgroup analyses have demon- strated an improved survival rate with revascularization compared with medical therapy in patients with CKD and multivessel CAD,478 480 despite the fact that the incidence of periprocedural complications (eg, death, MI, stroke, infec- tion, renal failure) is increased in patients with CKD com- pared with those without renal dysfunction. Some studies have shown that CABG is associated with a greater survival benefit than PCI among patients with severe renal 3.9.3. Completeness of Revascularization Most patients undergoing CABG receive complete or nearly complete revascularization, which seems to influence long- term prognosis positively.486 In contrast, complete revascu- larization is accomplished less often in subjects receiving PCI (eg, in 70% of patients), but the extent to which the absence of complete initial revascularization influences outcome is less clear. Rates of late survival and survival free of MI appear to be similar in patients with and without complete revascularization after PCI. Nevertheless, the need for subse- quent CABG is usually higher in those whose initial revas- cularization procedure was incomplete (compared with those with complete revascularization) after PCI.487 489 3.9.4.


Nevertheless, the need for subse- quent CABG is usually higher in those whose initial revas- cularization procedure was incomplete (compared with those with complete revascularization) after PCI.487 489 3.9.4. LV Systolic Dysfunction Several older studies and a meta-analysis of the data from these studies reported that patients with LV systolic dys- function (predominantly mild to moderate in severity) had better survival with CABG than with medical therapy alone.318,352 356 For patients with more severe LV systolic dysfunction, however, the evidence that CABG results in better survival compared with medical therapy is lacking. In the STICH (Surgical Treatment for Ischemic Heart Failure) trial of subjects with LVEF 35% with or without viability testing, CABG and GDMT resulted in similar rates of survival (death from any cause, the study s primary outcome) after 5 years of follow-up. For a number of secondary outcomes at this time point, including 1) death from any cause or hospitalization for heart failure, 2) death from any cause or hospitalization for cardiovascular causes, 3) death from any cause or hospitalization for any cause, or 4) death from any cause or revascularization with PCI or CABG, CABG was superior to GDMT. Although the primary out- come (death from any cause) was similar in the 2 treatment groups after an average of 5 years of follow-up, the data suggest the possibility that outcomes would differ if the follow-up were longer in duration; as a result, the study is being continued to provide follow-up for up to 10 years.371,372 Only very limited data comparing PCI with medical therapy in patients with LV systolic dysfunction are avail- able.356 In several ways, these data are suboptimal, in that many studies compared CABG with balloon angioplasty, many were retrospective, and many were based on cohort or registry data.


Although the primary out- come (death from any cause) was similar in the 2 treatment groups after an average of 5 years of follow-up, the data suggest the possibility that outcomes would differ if the follow-up were longer in duration; as a result, the study is being continued to provide follow-up for up to 10 years.371,372 Only very limited data comparing PCI with medical therapy in patients with LV systolic dysfunction are avail- able.356 In several ways, these data are suboptimal, in that many studies compared CABG with balloon angioplasty, many were retrospective, and many were based on cohort or registry data. Some of the studies demonstrated a similar survival rate in patients having CABG and PCI,359,451,490 492 whereas others showed that those undergoing CABG had better outcomes.320 The data that exist at present on revascu- larization in patients with CAD and LV systolic dysfunction are more robust for CABG than for PCI, although data from contemporary RCTs in this patient population are lacking. Therefore, the choice of revascularization in patients with CAD and LV systolic dysfunction is best based on clinical variables (eg, coronary anatomy, presence of diabetes melli- tus, presence of CKD), magnitude of LV systolic dysfunction, patient preferences, clinical judgment, and consultation be- tween the interventional cardiologist and the cardiac surgeon. 3.9.5.


Therefore, the choice of revascularization in patients with CAD and LV systolic dysfunction is best based on clinical variables (eg, coronary anatomy, presence of diabetes melli- tus, presence of CKD), magnitude of LV systolic dysfunction, patient preferences, clinical judgment, and consultation be- tween the interventional cardiologist and the cardiac surgeon. 3.9.5. Previous CABG In patients with recurrent angina after CABG, repeat revas- cularization is most likely to improve survival in subjects at highest risk, such as those with obstruction of the proximal LAD artery and extensive anterior ischemia.373 381 Patients with ischemia in other locations and those with a patent LIMA to the LAD artery are unlikely to experience a survival benefit from repeat revascularization.380 Cohort studies comparing PCI and CABG among post- CABG patients report similar rates of mid- and long-term survival after the 2 procedures.373,376 379,381,493 In the patient with previous CABG who is referred for revascularization for medically refractory ischemia, factors that may support the choice of repeat CABG include vessels unsuitable for PCI, Figure 2. 1-year mortality after revascularization for multivessel disease and diabetes mellitus. An OR of 1 suggests an advantage of CABG over PCI. ARTS I indicates Arterial Revascularization Therapy Study I474; BARI I, Bypass Angioplasty Revascularization Investiga- tion I362; CARDia, Coronary Artery Revascularization in Diabetes475; CI, confidence interval; DM, diabetes mellitus; MASS II, Medicine, Angioplasty, or Surgery Study II366; OR, odds ratio; SYNTAX, Synergy between Percutaneous Coronary Intervention with TAXUS and Cardiac Surgery; and W, weighted.364 Hillis et al 2011 ACCF/AHA CABG Guideline e675 number of diseased bypass grafts, availability of the IMA for grafting, chronically occluded coronary arteries, and good distal targets for bypass graft placement.


ARTS I indicates Arterial Revascularization Therapy Study I474; BARI I, Bypass Angioplasty Revascularization Investiga- tion I362; CARDia, Coronary Artery Revascularization in Diabetes475; CI, confidence interval; DM, diabetes mellitus; MASS II, Medicine, Angioplasty, or Surgery Study II366; OR, odds ratio; SYNTAX, Synergy between Percutaneous Coronary Intervention with TAXUS and Cardiac Surgery; and W, weighted.364 Hillis et al 2011 ACCF/AHA CABG Guideline e675 number of diseased bypass grafts, availability of the IMA for grafting, chronically occluded coronary arteries, and good distal targets for bypass graft placement. Factors favoring PCI over CABG include limited areas of ischemia causing symp- toms, suitable PCI targets, a patent graft to the LAD artery, poor CABG targets, and comorbid conditions. 3.9.6. Unstable Angina/Non ST-Elevation Myocardial Infarction The main difference between management of the patient with SIHD and the patient with UA/NSTEMI is that the impetus for revascularization is stronger in the setting of UA/ NSTEMI, because myocardial ischemia occurring as part of an ACS is potentially life threatening, and associated anginal symptoms are more likely to be reduced with a revascular- ization procedure than with GDMT.494 496 Thus, the indica- tions for revascularization are strengthened by the acuity of presentation, the extent of ischemia, and the ability to achieve full revascularization. The choice of revascularization method is generally dictated by the same considerations used to decide on PCI or CABG for patients with SIHD. 3.9.7. DAPT Compliance and Stent Thrombosis: Recommendation Class III: HARM 1.


DAPT Compliance and Stent Thrombosis: Recommendation Class III: HARM 1. PCI with coronary stenting (BMS or DES) should not be performed if the patient is not likely to be able to tolerate and comply with DAPT for the appropri- ate duration of treatment based on the type of stent implanted.497 500 (Level of Evidence: B) The risk of stent thrombosis is increased dramatically in patients who prematurely discontinue DAPT, and stent thrombosis is associated with a mortality rate of 20% to 45%.497 Because the risk of stent thrombosis with BMS is greatest in the first 14 to 30 days, this is the generally recommended minimum duration of DAPT therapy for these individuals. Consensus in clinical practice is to treat DES patients for at least 12 months with DAPT to avoid late (after 30 days) stent thrombosis.497,501 Therefore, the ability of the patient to tolerate and comply with at least 30 days of DAPT with BMS treatment and at least 12 months of DAPT with DES treatment is an important consideration in deciding whether to use PCI to treat patients with CAD. 3.10. TMR as an Adjunct to CABG TMR has been used on occasion in patients with severe angina refractory to GDMT in whom complete revascular- ization cannot be achieved with PCI and/or CABG.


TMR as an Adjunct to CABG TMR has been used on occasion in patients with severe angina refractory to GDMT in whom complete revascular- ization cannot be achieved with PCI and/or CABG. Although the mechanism by which TMR might be efficacious in these patients is unknown,502,503 several RCTs of TMR as sole therapy demonstrated a reduction in anginal symptoms com- pared with intensive medical therapy alone.397 399,504 506 A single randomized multicenter comparison of TMR (with a holmium:YAG laser) plus CABG and CABG alone in sub- jects in whom some myocardial segments were perfused by arteries considered not amenable to grafting showed a signif- icant reduction in perioperative mortality rate (1.5% versus 7.6%, respectively), and the survival benefit of the TMR CABG combination was present after 1 year of follow-up.400 At the same time, a large retrospective analysis of data from the STS National Cardiac Database, as well as a study of 169 patients from the Washington Hospital Center who under- went combined TMR CABG, showed no difference in ad- justed mortality rate compared with CABG alone.401,507 In short, a TMR CABG combination does not appear to im- prove survival compared with CABG alone. In selected patients, however, such a combination may be superior to CABG alone in relieving angina. 3.11. Hybrid Coronary Revascularization: Recommendations Class IIa 1. Hybrid coronary revascularization (defined as the planned combination of LIMA-to-LAD artery graft- ing and PCI of >1 non-LAD coronary arteries) is reasonable in patients with 1 or more of the follow- ing508 516 (Level of Evidence: B): a. Limitations to traditional CABG, such as heavily calcified proximal aorta or poor target vessels for CABG (but amenable to PCI); b. Lack of suitable graft conduits; c. Unfavorable LAD artery for PCI (ie, excessive vessel tortuosity or chronic total occlusion). Class IIb 1.


Lack of suitable graft conduits; c. Unfavorable LAD artery for PCI (ie, excessive vessel tortuosity or chronic total occlusion). Class IIb 1. Hybrid coronary revascularization (defined as the planned combination of LIMA-to-LAD artery grafting and PCI of >1 non-LAD coronary arter- ies) may be reasonable as an alternative to multi- vessel PCI or CABG in an attempt to improve the overall risk benefit ratio of the procedures. (Level of Evidence: C) Hybrid coronary revascularization, defined as the planned combination of LIMA-to-LAD artery grafting and PCI of 1 non-LAD coronary arteries,515 is intended to combine the advantages of CABG (ie, durability of the LIMA graft) and PCI.516 Patients with multivessel CAD (eg, LAD and 1 non-LAD stenoses) and an indication for revascularization are potentially eligible for this approach. Hybrid revascular- ization is ideal in patients in whom technical or anatomic limitations to CABG or PCI alone may be present and for whom minimizing the invasiveness (and therefore the risk of morbidity and mortality) of surgical intervention is pre- ferred510 (eg, patients with severe preexisting comorbidities, recent MI, a lack of suitable graft conduits, a heavily calcified ascending aorta, or a non-LAD coronary artery unsuitable for bypass but amenable to PCI, and situations in which PCI of the LAD artery is not feasible because of excessive tortuosity or chronic total occlusion). Hybrid coronary revascularization may be performed in a hybrid suite in one operative setting or as a staged procedure (ie, PCI and CABG performed in 2 different operative suites, separated by hours to 2 days, but typically during the same hospital stay). Because most hospitals lack a hybrid operating room, staged procedures are usually performed.


Because most hospitals lack a hybrid operating room, staged procedures are usually performed. With the staged procedure, CABG before PCI is preferred, because this approach allows the interventional cardiologist to 1) verify the patency of the LIMA-to-LAD artery graft before attempting PCI of other vessels and 2) minimize the risk of perioperative bleeding that would occur if CABG were performed after PCI (ie, while the patient is receiving DAPT). Because minimally invasive CABG may be associated with lower graft patency rates compared with CABG performed through a midline sternotomy, it seems prudent to angio- graphically image all grafts performed through a minimally invasive approach to confirm graft patency.510 To date, no RCTs involving hybrid coronary revascular- ization have been published. Over the past 10 years, several small, retrospective series of hybrid revascularization using minimally invasive CABG and PCI have reported low mor- tality rates (0 to 2%) and event-free survival rates of 83% to 92% at 6 to 12 months of follow-up. The few series that have compared the outcomes of hybrid coronary revascularization with standard CABG report similar outcomes at 30 days and 4. Perioperative Management 4.1. Preoperative Antiplatelet Therapy: Recommendations Class I 1. Aspirin (100 mg to 325 mg daily) should be admin- istered to CABG patients preoperatively.517 519 (Level of Evidence: B) 2. In patients referred for elective CABG, clopidogrel and ticagrelor should be discontinued for at least 5 days before surgery520 522 (Level of Evidence: B) and prasugrel for at least 7 days (Level of Evidence: C) to limit blood transfusions. 3. In patients referred for urgent CABG, clopidogrel and ticagrelor should be discontinued for at least 24 hours to reduce major bleeding complications.521,523 525 (Level of Evidence: B) 4.


In patients referred for urgent CABG, clopidogrel and ticagrelor should be discontinued for at least 24 hours to reduce major bleeding complications.521,523 525 (Level of Evidence: B) 4. In patients referred for CABG, short-acting intra- venous glycoprotein IIb/IIIa inhibitors (eptifibatide or tirofiban) should be discontinued for at least 2 to 4 hours before surgery526,527 and abciximab for at least 12 hours beforehand528 to limit blood loss and transfusions. (Level of Evidence: B) Class IIb 1. In patients referred for urgent CABG, it may be reasonable to perform surgery less than 5 days after clopidogrel or ticagrelor has been discontinued and less than 7 days after prasugrel has been discontin- ued. (Level of Evidence: C) Nearly all patients with UA or recent MI in whom CABG is performed will be taking aspirin; CABG can be performed safely in these individuals, with only a modest increase in bleeding risk. Preoperative aspirin use reduces operative morbidity and mortality rates.517,518 Although the use of thienopyridines (clopidogrel or prasugrel) is associated with improved outcomes in subjects with UA or NSTEMI,305,306 their use is associated with an increase in post-CABG bleeding and need for transfusions.520,522,529 533 The risk of major bleeding complications (ie, pericardial tampon- ade or reoperation) is increased when CABG is performed 24 hours after clopidogrel s discontinuation.524,525 Con- versely, no increase in bleeding or transfusions is noted when CABG is performed 5 days after clopidogrel has been stopped.529,532 The magnitude of bleeding risk when CABG is performed 1 to 4 days after the discontinuation of clopidogrel is less certain. Although the incidence of life-threatening bleeding does not appear to be significantly increased during this time, an increase in blood transfusions is likely.523,524,529,531 Accordingly, from the perspective of blood conservation, it is reasonable to delay elective CABG for 5 days after discontinuing clopidogrel.


Although the incidence of life-threatening bleeding does not appear to be significantly increased during this time, an increase in blood transfusions is likely.523,524,529,531 Accordingly, from the perspective of blood conservation, it is reasonable to delay elective CABG for 5 days after discontinuing clopidogrel. For patients requiring more urgent CABG, it can be performed 24 hours after clopidogrel has been stopped with little or no increased risk of major bleeding. Approximately two thirds of clopidogrel- treated patients undergo CABG 5 days after clopidogrel discontinuation,529,532 driven largely by concerns for patient stability, resource utilization, patient preference, and the confidence of the surgical team in managing hemostasis. Little experience with CABG in patients treated with prasu- grel has been reported. In the TRITON-TIMI 38 (Trial to Assess Improvement in Therapeutic Outcomes by Optimizing Platelet Inhibition With Prasugrel Thrombolysis in Myocar- dial Infarction) trial, the incidence of CABG-related major bleeding was higher in prasugrel-treated patients than in those possible, therefore, CABG should be delayed for 7 days after prasugrel is discontinued.533 Ticagrelor, an oral agent that binds reversibly to the platelet P2Y12 receptor, provides faster, more effective, and more consistent inhibition of platelet aggregation and more rapid recovery of platelet function after discontinuation than clopi- dogrel.534 In the PLATO (Platelet Inhibition and Patient Out- comes) trial, 632 patients in the ticagrelor group and 629 in the clopidogrel group underwent CABG within 7 days of the last dose of study drug.521 Although the study protocol recom- mended waiting 5 days after stopping clopidogrel and 24 to 72 hours after ticagrelor, many patients underwent surgery before the recommended waiting times. The rates of major bleeding (59.3% with ticagrelor, 57.6% with clopidogrel) and transfusion requirements (55.7% with ticagrelor, 56.5% with clopidogrel) were similar.


The rates of major bleeding (59.3% with ticagrelor, 57.6% with clopidogrel) and transfusion requirements (55.7% with ticagrelor, 56.5% with clopidogrel) were similar. Furthermore, no difference in bleeding was noted between ticagrelor and clopidogrel with respect to time from last dose of study drug, even when CABG was performed 1, 2, or 3 days after discontinuation. On the basis of these data, it does not appear that the more rapid recovery of platelet function seen in ticagrelor pharmacokinetic studies translates to a lower risk of bleeding or less need for transfusion compared with clopidogrel when CABG is performed early (ie, 5 days) after drug discontinuation. 4.2. Postoperative Antiplatelet Therapy: Recommendations Class I 1. If aspirin (100 mg to 325 mg daily) was not initiated preoperatively, it should be initiated within 6 hours postoperatively and then continued indefinitely to Hillis et al 2011 ACCF/AHA CABG Guideline e677 reduce the occurrence of SVG closure and adverse cardiovascular events.519,535,536 (Level of Evidence: A) Class IIa 1. For patients undergoing CABG, clopidogrel 75 mg daily is a reasonable alternative in patients who are intolerant of or allergic to aspirin. (Level of Evi- dence: C) See Online Data Supplement 23 for additional data on postoperative antiplatelet therapy. Aspirin significantly improves SVG patency rates, partic- ularly during the first postoperative year. Because arterial graft patency rates are high even in the absence of antiplatelet therapy, the administration of such therapy has not shown an improvement.


Because arterial graft patency rates are high even in the absence of antiplatelet therapy, the administration of such therapy has not shown an improvement. Aspirin administration before CABG offers no improvement in subsequent SVG patency compared with its early postoperative initiation.535 Prospective controlled trials have demonstrated a graft patency benefit when aspirin was started 1, 7, or 24 hours after operation103,537; in contrast, the benefit of postoperative aspirin on SVG patency was lost when it was initiated 48 hours after surgery.538 Dosing regimens ranging from 100 mg daily to 325 mg 3 times daily appear to be efficacious.539 As the grafted recipient s coronary arterial luminal diameter increases, SVG patency rates improve, and the relative advantage of aspirin over placebo is reduced.540 Although aspirin doses of 100 mg daily have been used for prevention of adverse events in patients with CAD, they may be less efficacious than higher doses in optimizing SVG patency.541 Enteric-coated aspirin, 75 mg, has been associated with suboptimal inhibition of platelet aggregation in 44% of patients with stable cardiovascular disease, suggesting that soluble aspirin may be preferred if low-dose aspirin is used.542 When given within 48 hours after CABG, aspirin has been shown to reduce subsequent rates of mortality, MI, stroke, renal failure, and bowel infarction.519 Although ticlopidine is efficacious at inhibiting platelet aggregation, it offers no advantage over aspirin except as an alternative in the truly aspirin-allergic patient.543 In addition, its use may be associated with potentially life-threatening neutropenia, a rare adverse effect, such that white blood cell counts should be monitored repetitively after initiating it. Dipyridamole and warfarin add nothing to the effect of aspirin on SVG patency,544,545 and use of the latter may be associated with an increased risk for bleeding compared with Clopidogrel is associated with fewer adverse effects than ticlopidine.


Dipyridamole and warfarin add nothing to the effect of aspirin on SVG patency,544,545 and use of the latter may be associated with an increased risk for bleeding compared with Clopidogrel is associated with fewer adverse effects than ticlopidine. Severe leukopenia occurs very rarely.546,547 A subset analysis of CABG patients from the CURE (Clopi- dogrel in Unstable Angina to Prevent Recurrent Ischemic Events) trial suggested that clopidogrel reduced the occur- rence of cardiovascular death, MI, and stroke (14.5%) com- pared with placebo (16.2%). This benefit occurred primarily before surgery, however, and after CABG a difference in primary endpoints between groups was not demonstrable. Clopidogrel was stopped a median of 10 days before surgery and was restarted postoperatively in 75.3% of patients as- signed to receive it. All patients received aspirin, 75 mg to 325 mg daily, but the details of aspirin administration in the study groups were not described.530 4.3. Management of Hyperlipidemia: Recommendations Class I 1. All patients undergoing CABG should receive statin therapy, unless contraindicated.545,548 559 (Level of Evidence: A) 2. In patients undergoing CABG, an adequate dose of statin should be used to reduce LDL cholesterol to less than 100 mg/dL and to achieve at least a 30% lowering of LDL cholesterol.548 552 (Level of Evi- dence: C) Class IIa 1. In patients undergoing CABG, it is reasonable to treat with statin therapy to lower the LDL choles- terol to less than 70 mg/dL in very high-risk* patients.549 551,561 563 (Level of Evidence: C) 2. For patients undergoing urgent or emergency CABG who are not taking a statin, it is reasonable to initiate high-dose statin therapy immediately.564 (Level of Evidence: C) Class III: HARM 1.


For patients undergoing urgent or emergency CABG who are not taking a statin, it is reasonable to initiate high-dose statin therapy immediately.564 (Level of Evidence: C) Class III: HARM 1. Discontinuation of statin or other dyslipidemic ther- apy is not recommended before or after CABG in patients without adverse reactions to therapy.565 567 (Level of Evidence: B) See Online Data Supplement 24 for additional data on management of hyperlipidemia. In patients with CAD, treatment of hyperlipidemia with therapeutic lifestyle changes and medications reduces the risk of nonfatal MI and death. The goal of such therapy is to reduce the LDL cholesterol level to 100 mg/dL.563 Statins are the most commonly prescribed agents for achieving this goal.563 Studies of lipid-lowering therapy in CABG patients have demonstrated that lowering LDL cholesterol with statins influences post-CABG outcomes, and aggressive LDL cholesterol lowering (to 60 to 85 mg/dL) is associated with a reduced rate of graft atherosclerosis and repeat revasculariza- tion compared with only moderate lowering (130 to 140 mg/dL).545,556 In the latter study, both groups of subjects initially received lovastatin at different doses (40 mg in the aggressive lowering group versus 2.5 mg in the moderate group), and cholestyramine was added if LDL cholesterol goals were not met with lovastatin alone. Of note, patients were maintained on therapy for 1 year, and as many as 11 years, after CABG.


Of note, patients were maintained on therapy for 1 year, and as many as 11 years, after CABG. The PROVE IT TIMI-22 (Pravastatin or Atorvastatin Evaluation and Infection Therapy: Thrombolysis in Myocar- dial Infarction) trial randomly assigned patients with ACS, a Presence of established cardiovascular disease plus 1) multiple major risk factors (especially diabetes), 2) severe and poorly controlled risk factors (especially continued cigarette smoking), 3) multiple risk factors of the metabolic syndrome (especially high triglycerides 200 mg/dL plus non high-density lipoprotein cholesterol 130 mg/dL with low high-density lipoprotein cholesterol [ 40 mg/dL]), and 4) acute coronary syndromes. minority of whom had previous CABG, to intensive (LDL cholesterol goal 70 mg/dL) versus standard (LDL choles- terol goal 100 mg/dL) lipid-lowering therapy. The benefit of intensive therapy (a reduction in death, MI, recurrent UA, repeat revascularization, or stroke) was observed within 30 days.561 In the occasional subject who cannot take statins, alternative hypolipidemic agents, such as bile acid seques- trants, niacin, and fibrates, should be considered, in accor- dance with National Cholesterol Education Program: Adult Treatment Panel III guidelines.563 4.3.1. Timing of Statin Use and CABG Outcomes As noted, the benefits of post-CABG LDL lowering with statins have been reported previously, but no prospective studies of the impact of preoperative LDL cholesterol lower- ing on post-CABG outcomes are available.


Timing of Statin Use and CABG Outcomes As noted, the benefits of post-CABG LDL lowering with statins have been reported previously, but no prospective studies of the impact of preoperative LDL cholesterol lower- ing on post-CABG outcomes are available. One small ran- domized comparison of preoperative placebo and a statin (initiated 1 week before CABG) showed a reduction in elevated perioperative cardiac biomarkers with statin ther- apy.554 Several nonrandomized, retrospective studies have noted an association between preoperative statin use and reduced rates of postoperative nonfatal MI and death.553,555,557 559 In addition, preoperative statin use has been associated with reduced rates of postoperative atrial fibrillation (AF),571,572 neurological dysfunction,555,573,574 re- nal dysfunction,575 and infection.576 Untreated hyperlipidemic patients have been shown to have a higher risk of post-CABG events than that of treated hyperlipidemic patients and those with normal serum lipid concentrations.567 In patients under- going CABG who are not on statin therapy or at LDL goal, it seems reasonable to initiate intensive statin therapy preoper- atively (ie, no later than 1 week before surgery). Postoperatively, statin use should be resumed when the patient is able to take oral medications and should be continued indefinitely. Patients in whom statins were discon- tinued after CABG have been shown to have a higher mortality rate than those in whom statins were continued 4.3.1.1. Potential Adverse Effects of Perioperative Statin Therapy The most common adverse effects reported with statin use are myopathy and hepatotoxicity.


Potential Adverse Effects of Perioperative Statin Therapy The most common adverse effects reported with statin use are myopathy and hepatotoxicity. Muscle aches have been re- ported in about 5% of patients treated with statins, although several pooled analyses of RCTs have shown a similar rate of muscle aches with placebo.577 Myositis, defined as muscle pain with a serum creatine kinase 10 times the upper limit of normal, occurs in 0.1% to 0.2% of statin users, and rhabdomyolysis occurs in 0.02%.578,579 In addition, approxi- mately 2% of patients are observed to have elevated liver enzymes (ie, alanine and aspartate transaminases) in the weeks to months after statin initiation, but no data are available to suggest that these elevations are associated with permanent hepatotoxicity or an increased risk of hepatitis. Nonetheless, the presence of active or chronic liver disease is a contraindication to statin use, and patients initiated on a statin should be monitored for the development of myositis or rhabdomyolosis, either of which would mandate its 4.4. Hormonal Manipulation: Recommendations Class I 1. Use of continuous intravenous insulin to achieve and maintain an early postoperative blood glucose con- centration less than or equal to 180 mg/dL while avoiding hypoglycemia is indicated to reduce the incidence of adverse events, including deep sternal wound infection, after CABG.581 583 (Level of Evi- dence: B) Class IIb 1. The use of continuous intravenous insulin designed to achieve a target intraoperative blood glucose concentration less than 140 mg/dL has uncertain effectiveness.584 586 (Level of Evidence: B) Class III: HARM 1. Postmenopausal hormonal therapy (estrogen/pro- gesterone) should not be administered to women undergoing CABG.587 589 (Level of Evidence: B) 4.4.1. Glucose Control Hyperglycemia often occurs during and after CABG, partic- ularly when CABG is performed on pump.


Glucose Control Hyperglycemia often occurs during and after CABG, partic- ularly when CABG is performed on pump. Intraoperative hyperglycemia is associated with an increased morbidity rate in patients with diabetes590 and with excess mortality in patients with and without diabetes.591 Hyperglycemia during CPB is an independent risk factor for death in patients undergoing cardiac surgery. A retrospective observational study of 409 cardiac surgical patients identified intraoperative hyperglycemia as an independent risk factor for perioperative complications, including death, and calculated a 34% in- creased likelihood of postoperative complications for every 20-mg/dL increase in blood glucose concentration 100 mg/dL during surgery.592 An RCT of critically ill patients, many of whom had high-risk cardiac surgery, found reduced morbidity and mortality rates in those whose blood glucose was tightly controlled,583 and follow-up of these subjects showed that this benefit persisted for up to 4 years.582 The Portland Diabetes Project, begun in 1992, was the first large study to elucidate the detrimental effects of hyperglycemia in relation to CABG outcomes. This prospective observational study described the evolution in management of cardiac surgical patients with diabetes mellitus from a strategy of intermittent subcutaneous injections of insulin to one of continuous intrave- nous insulin infusion with decreasing target glucose concentra- tions.


This prospective observational study described the evolution in management of cardiac surgical patients with diabetes mellitus from a strategy of intermittent subcutaneous injections of insulin to one of continuous intrave- nous insulin infusion with decreasing target glucose concentra- tions. As this management strategy evolved, the upper target serum glucose concentrations declined from 200 mg/dL to 110 mg/dL, with which significant reductions in operative and cardiac-related death (arrhythmias and acute ventricular failure) were noted.581 In addition, continuous intravenous insulin to maintain a serum glucose concentration of 120 mg/dL to 160 mg/dL resulted in a reduced incidence of deep sternal wound infection.593,594 As a result, most centers now emphasize tight glucose control (target serum glucose concentration 180 mg/ dL, accomplished with a continuous intravenous insulin infu- sion) during surgery and until the morning of the third postop- erative day. Hillis et al 2011 ACCF/AHA CABG Guideline e679 Whether extremely tight intraoperative glucose control can further reduce morbidity or mortality rate is controversial. A prospective trial from the Mayo Clinic randomly assigned 400 patients to intensive treatment (continuous insulin infu- sion during surgery) or conventional treatment (insulin given only for a glucose concentration 200 mg/dL).586 Postoper- ative ICU management was similar in the 2 groups.


A prospective trial from the Mayo Clinic randomly assigned 400 patients to intensive treatment (continuous insulin infu- sion during surgery) or conventional treatment (insulin given only for a glucose concentration 200 mg/dL).586 Postoper- ative ICU management was similar in the 2 groups. Although no difference was noted between groups in a composite endpoint of death, deep sternal wound infection, prolonged ventilation, cardiac arrhythmias, stroke, or renal failure within 30 days of surgery, intensive treatment caused an increased incidence of death and stroke, thereby raising concerns about this intervention.586 In a prospective RCT in 381 CABG patients without diabetes, those with an intraop- erative blood glucose concentration 100 mg/dL were as- signed to an insulin infusion or no treatment.584 Those receiving insulin had lower intraoperative glucose concentra- tions, but no difference between groups was observed in the occurrence of new neurological, neuro-ophthalmologic, or neurobehavioral deficits or neurology-related deaths. Of note, no difference in need for inotropic support, hospital length of stay, or operative mortality rate was seen between the groups.584 A retrospective analysis of intraoperative and postoperative ICU glucose concentrations in 4300 patients undergoing cardiac surgery at the Cleveland Clinic observed that a blood glucose concentration 200 mg/dL in the operating room or ICU was associated with worse outcomes, but intraoperative glucose concentrations 140 mg/dL were not associated with improved outcomes compared with se- vere hyperglycemia, despite infrequent hypoglycemia. Dia- betic status did not influence the effects of hyperglycemia.585 In short, until additional information is available, extremely tight intraoperative glucose control is not recommended.


Dia- betic status did not influence the effects of hyperglycemia.585 In short, until additional information is available, extremely tight intraoperative glucose control is not recommended. Although the management of blood glucose before surgery in patients with and without diabetes mellitus is not well studied, an increased incidence of adverse outcomes has been noted in patients with poor preoperative glycemic con- trol.593,595 As a result, most centers now attempt to optimize glucose control before surgery, attempting to achieve a target glucose concentration 180 mg/dL with continuous intrave- nous insulin. Measuring preoperative hemoglobin A1c con- centrations may be helpful in assessing the adequacy of preoperative glycemic control and identifying patients at risk for postoperative hyperglycemia.596 4.4.2. Postmenopausal Hormone Therapy Postmenopausal hormone therapy was shown previously to reduce the risk of cardiac-related death. However, more contemporary published RCTs have suggested that it may have adverse cardiovascular effects. The Women s Health Initiative randomly assigned 16 000 healthy postmeno- pausal women to placebo or continuous combined estrogen progestin therapy. Hormone therapy was discontinued early because of an increased risk of breast cancer in those receiving it. Additionally, subjects receiving it had an in- creased incidence of cardiac ischemic events (29% increase, mainly nonfatal MI), stroke, and venous thromboembo- lism.588 A secondary prevention trial, HERS (Heart and Estrogen/Progestin Replacement Study), randomly assigned 2763 postmenopausal women with known CAD to continu- ous estrogen/progestin or placebo, after which they were followed up for a mean of 4.1 years.587 No difference in the primary endpoints of nonfatal MI and CAD death was noted, but those receiving hormone therapy had a greater incidence of deep venous thrombosis and other thromboembolic events. This predisposition to thrombosis has raised concerns that hormone therapy may cause adverse events at the time of CABG.


This predisposition to thrombosis has raised concerns that hormone therapy may cause adverse events at the time of CABG. A prospective RCT comparing hormone therapy to placebo in postmenopausal women after CABG was initiated in 1998 but was stopped when the Women s Health Initiative trial results were reported.589 Eighty-three subjects were enrolled, and 45 underwent angiographic follow-up at 42 months. Angiographic progression of CAD in nonbypassed coronary arteries was greater in patients receiving hormone therapy, although less progression of disease was observed in SVGs. Postoperative angioplasty was performed in 8 hor- mone therapy patients and only 1 placebo subject (P 0.05). On the basis of these data, it is not recommended that post-menopausal hormone therapy be initiated in women undergoing CABG, and it may be reasonable to discontinue it in those scheduled for elective CABG. 4.4.3. CABG in Patients With Hypothyroidism Subclinical hypothyroidism (thyroid-stimulating hormone concentration, 4.50 mIU/L to 19.9 mIU/L) occurs commonly in patients with CAD. In a meta-analysis of 55 000 subjects with CAD, those with subclinical hypothyroidism did not have an increase in total deaths, but the CAD mortality rate was increased, particularly in those with thyroid-stimulating The risks of CABG in hypothyroid patients are poorly defined.


In a meta-analysis of 55 000 subjects with CAD, those with subclinical hypothyroidism did not have an increase in total deaths, but the CAD mortality rate was increased, particularly in those with thyroid-stimulating The risks of CABG in hypothyroid patients are poorly defined. A retrospective study of hypothyroid patients under- going CABG had a higher incidence of heart failure and gastrointestinal complications and a lower incidence of post- operative fever than did members of a matched euthyroid group.598 Patients with subclinical hypothyroidism may be at increased risk for developing AF after CABG,599 and 1 study even suggested that triiodothyronine supplementation in pa- tients undergoing CABG (including those who are euthyroid) decreased the incidence of postoperative AF.600 Conversely, controlled studies of triiodothyronine in subjects undergoing CABG have shown no benefit.601,602 Rarely, patients may develop severe hypothyroidism after CABG, which manifests as lethargy, prolonged required ventilation, and hypoten- sion.603 Thyroid replacement is indicated in these individuals. 4.5. Perioperative Beta Blockers: Recommendations Class I 1. Beta blockers should be administered for at least 24 hours before CABG to all patients without contra- indications to reduce the incidence or clinical se- quelae of postoperative AF.604 608,608a 608c (Level of Evidence: B) 2. Beta blockers should be reinstituted as soon as possible after CABG in all patients without contra- indications to reduce the incidence or clinical se- quelae of AF.604 608,608a 608c (Level of Evidence: B) 3. Beta blockers should be prescribed to all CABG patients without contraindications at the time of hospital discharge. (Level of Evidence: C) Class IIa 1. Preoperative use of beta blockers in patients without contraindications, particularly in those with an LVEF greater than 30%, can be effective in reduc- ing the risk of in-hospital mortality.609 611 (Level of Evidence: B) 2.


Preoperative use of beta blockers in patients without contraindications, particularly in those with an LVEF greater than 30%, can be effective in reduc- ing the risk of in-hospital mortality.609 611 (Level of Evidence: B) 2. Beta blockers can be effective in reducing the inci- dence of perioperative myocardial ischemia.612 615 (Level of Evidence: B) 3. Intravenous administration of beta blockers in clin- ically stable patients unable to take oral medications is reasonable in the early postoperative period.616 (Level of Evidence: B) Class IIb 1. The effectiveness of preoperative beta blockers in reducing inhospital mortality rate in patients with LVEF less than 30% is uncertain.609,617 (Level of Evidence: B) See Online Data Supplement 25 for additional data on beta blockers.


The effectiveness of preoperative beta blockers in reducing inhospital mortality rate in patients with LVEF less than 30% is uncertain.609,617 (Level of Evidence: B) See Online Data Supplement 25 for additional data on beta blockers. Because beta blockers have been shown to reduce the inci- dence of postoperative AF in CABG patients who are receiving them preoperatively604,605,608 (Section 5.2.5), the STS and AHA recommend that they be administered preoperatively to all patients without contraindications and then be continued post- operatively.618,619 Despite this recommendation, uncertainty ex- ists about their efficacy in subjects not receiving them preoper- atively; in this patient population, their use appears to lengthen hospital stay and not to reduce the incidence of postoperative AF.604,607 Their efficacy in preventing or treating perioperative myocardial ischemia is supported by the results of observational studies and small RCTs.612 614 Although a meta-analysis of available data did not show an improvement in outcomes with perioperative beta blockers,615 observational analyses suggest that preoperative beta-blocker use is associated with a reduction in perioperative deaths.609 611 Another analysis of data from 629 877 patients reported a mortality rate of 2.8% in those receiving beta blockers versus 3.4% in those not receiving Few data are available on the pharmacokinetic disposition of beta blockers in the early postoperative period, when an alteration in gastrointestinal perfusion may adversely affect their absorption after oral administration.


Because beta blockers have been shown to reduce the inci- dence of postoperative AF in CABG patients who are receiving them preoperatively604,605,608 (Section 5.2.5), the STS and AHA recommend that they be administered preoperatively to all patients without contraindications and then be continued post- operatively.618,619 Despite this recommendation, uncertainty ex- ists about their efficacy in subjects not receiving them preoper- atively; in this patient population, their use appears to lengthen hospital stay and not to reduce the incidence of postoperative AF.604,607 Their efficacy in preventing or treating perioperative myocardial ischemia is supported by the results of observational studies and small RCTs.612 614 Although a meta-analysis of available data did not show an improvement in outcomes with perioperative beta blockers,615 observational analyses suggest that preoperative beta-blocker use is associated with a reduction in perioperative deaths.609 611 Another analysis of data from 629 877 patients reported a mortality rate of 2.8% in those receiving beta blockers versus 3.4% in those not receiving Few data are available on the pharmacokinetic disposition of beta blockers in the early postoperative period, when an alteration in gastrointestinal perfusion may adversely affect their absorption after oral administration. An RCT demon- strated a significant reduction in the incidence of postopera- tive AF when a continuous intravenous infusion of meto- prolol was used rather than oral administration.616 The efficacy of beta-blocker use in CABG patients after hospital discharge is uncertain, as data from 2 RCTs and 1 large detailed observational analysis suggest that they exert no benefit over 2 years postoperatively.621 623 In contrast, some observa- tional analyses have reported that they are, in fact, efficacious in high-risk subgroups (eg, those with perioperative myocardial ischemia or elderly subjects with heart failure).624 A contempo- rary analysis of prescription data from 3,102 Canadian patients, 83% of whom were prescribed a beta blocker at the time of discharge, reported that those receiving beta blockers had a reduced mortality rate during a mean follow-up of 75 months.625 Of note, improved survival was noted in all patient subgroups receiving beta blockers, even including those without perioper- ative myocardial ischemia or heart failure.


An RCT demon- strated a significant reduction in the incidence of postopera- tive AF when a continuous intravenous infusion of meto- prolol was used rather than oral administration.616 The efficacy of beta-blocker use in CABG patients after hospital discharge is uncertain, as data from 2 RCTs and 1 large detailed observational analysis suggest that they exert no benefit over 2 years postoperatively.621 623 In contrast, some observa- tional analyses have reported that they are, in fact, efficacious in high-risk subgroups (eg, those with perioperative myocardial ischemia or elderly subjects with heart failure).624 A contempo- rary analysis of prescription data from 3,102 Canadian patients, 83% of whom were prescribed a beta blocker at the time of discharge, reported that those receiving beta blockers had a reduced mortality rate during a mean follow-up of 75 months.625 Of note, improved survival was noted in all patient subgroups receiving beta blockers, even including those without perioper- ative myocardial ischemia or heart failure. 4.6. ACE Inhibitors/ARBs: Recommendations Class I 1. ACE inhibitors and ARBs given before CABG should be reinstituted postoperatively once the pa- tient is stable, unless contraindicated.622,626,627 (Level of Evidence: B) 2. ACE inhibitors or ARBs should be initiated postop- eratively and continued indefinitely in CABG pa- tients who were not receiving them preoperatively, who are stable, and who have an LVEF less than or equal to 40%, hypertension, diabetes mellitus, or CKD, unless contraindicated.622,627,627a,627b (Level of Evidence: A) Class IIa 1. It is reasonable to initiate ACE inhibitors or ARBs postoperatively and to continue them indefinitely in all CABG patients who were not receiving them preoperatively and are considered to be at low risk (ie, those with a normal LVEF in whom cardiovas- cular risk factors are well controlled), unless contra- indicated.622,627 630 (Level of Evidence: B) Class IIb 1.


It is reasonable to initiate ACE inhibitors or ARBs postoperatively and to continue them indefinitely in all CABG patients who were not receiving them preoperatively and are considered to be at low risk (ie, those with a normal LVEF in whom cardiovas- cular risk factors are well controlled), unless contra- indicated.622,627 630 (Level of Evidence: B) Class IIb 1. The safety of the preoperative administration of ACE inhibitors or ARBs in patients on chronic therapy is uncertain.631 636 (Level of Evidence: B) 2. The safety of initiating ACE inhibitors or ARBs before hospital discharge is not well estab- lished.622,628,630,640 (Level of Evidence: B) See Online Data Supplements 26 and 27 for additional data on ACE inhibitors. ACE inhibitors and ARBs are known to exert cardiovasculo- protective actions, particularly in subjects with LV systolic dysfunction, hypertension, diabetes mellitus, or chronic renal insufficiency.626 Nonetheless, the safety and effectiveness of preoperative ACE inhibitors and ARBs in patients undergoing cardiac or noncardiac surgery is uncertain638 because their administration has been associated with intraoperative hypoten- sion as well as a blunted response to pressors and inotropic agents after induction of anesthesia. Of particular concern during cardiac surgery is their reported association with severe hypo- tension after CPB (so-called vasoplegia syndrome) and postop- erative renal dysfunction.631,639 Although it has been postulated that these agents may protect against the development of postoperative AF, published studies have reached conflicting conclusions in this regard.634,636 The safety and efficacy of ACE inhibitors and ARBs after CABG in previously na ve low- to moderate-risk patients (ie, subjects without diabetes mellitus or renal insufficiency and with or Hillis et al 2011 ACCF/AHA CABG Guideline e681 without asymptomatic moderate LV systolic dysfunction) are uncertain; furthermore, ACE inhibitors and ARBs must be used with caution in these subjects.


Of particular concern during cardiac surgery is their reported association with severe hypo- tension after CPB (so-called vasoplegia syndrome) and postop- erative renal dysfunction.631,639 Although it has been postulated that these agents may protect against the development of postoperative AF, published studies have reached conflicting conclusions in this regard.634,636 The safety and efficacy of ACE inhibitors and ARBs after CABG in previously na ve low- to moderate-risk patients (ie, subjects without diabetes mellitus or renal insufficiency and with or Hillis et al 2011 ACCF/AHA CABG Guideline e681 without asymptomatic moderate LV systolic dysfunction) are uncertain; furthermore, ACE inhibitors and ARBs must be used with caution in these subjects. They should not be instituted in the immediate postoperative period if the systolic arterial pres- sure is 100 mm Hg or if the patient develops hypotension in the hospital after receiving them.


They should not be instituted in the immediate postoperative period if the systolic arterial pres- sure is 100 mm Hg or if the patient develops hypotension in the hospital after receiving them. The IMAGINE (Ischemia Management With Accupril Post Bypass Graft via Inhibition of Angiotensin Converting Enzyme) study failed to show a bene- ficial effect of postoperative ACE inhibitor therapy 3 years after CABG, instead noting an increase in adverse events, particularly recurrent angina in the first 3 months of therapy.630 A subanal- ysis of the data from patients enrolled in EUROPA (European Trial on the Reduction of Cardiac Events with Perindopril in Stable Coronary Artery Disease) with previous revascularization (CABG or PCI no sooner than 6 months before enrollment) suggested a primary and secondary prevention benefit over a 4.2-year follow-up period; however, an analysis of the data from almost 3000 patients in the PREVENT IV (PRoject of Ex-vivo Vein graft ENgineering via Transfection) trial, all of whom were taking either ACE inhibitors or ARBs at the time of hospital discharge, failed to demonstrate a significant reduction in death or MI after 2 years of follow-up in ideal candidates (based on P NS), whereas significance was achieved in non-ideal candi- 4.7. Smoking Cessation: Recommendations Class I 1. All smokers should receive in-hospital educational counseling and be offered smoking cessation therapy during CABG hospitalization.642 644 (Level of Evi- dence: A) Class IIb 1. The effectiveness of pharmacological therapy for smoking cessation offered to patients before hospital discharge is uncertain. (Level of Evidence: C) See Online Data Supplement 28 for additional data on smoking cessation. Smoking cessation after CABG is associated with a sub- stantial reduction in subsequent MACE, including MI and death.


Smoking cessation after CABG is associated with a sub- stantial reduction in subsequent MACE, including MI and death. Data from the randomized portion of the CASS study showed 10-year survival rates of 82% among the 468 patients who quit smoking after CABG and only 77% in the 312 who continued to smoke (P 0.025).645 Those who continued to smoke were more likely to have recurrent angina and to require repeat hospitalization. Data from the CASS registry demonstrated 5-year mortality rates of 22% for those who continued to smoke and only 15% for those who successfully quit smoking after CABG (RR: 1.55; 95% CI: 1.29 to 1.85).646 Similar favorable outcomes with smoking cessation were reported from the MRFIT (Multiple Risk Factor Inter- vention Trial), in which the impact of smoking cessation on MACE was assessed after 10.5 years of follow-up in 12 866 men; the risk of death was greater among smokers than non- smokers (RR: 1.57).647 Notably, the risk of dying from cardiac causes was lower for those who successfully quit than for nonquitters after only 1 year of smoking cessation (RR: 0.63), and it remained so in those who quit for at least the first 3 years of the study (RR: 0.38).647 The beneficial effects of smoking cessation after CABG seem to be durable during long-term follow-up (ie, even 30 years postoperatively).648 650 In fact, smoking cessation was associated with a reduction in mor- tality rate of greater magnitude than that resulting from any other treatment or intervention after CABG.649 In these long-term follow-up studies, patients who continued to smoke had significantly higher rates of MI, reoperation, and death. Smoking is a powerful independent predictor of sudden cardiac death in patients with CAD (HR: 2.47; 95% CI: 1.46 to 4.19).


Smoking is a powerful independent predictor of sudden cardiac death in patients with CAD (HR: 2.47; 95% CI: 1.46 to 4.19). It has been associated with accelerated disease and occlusion of SVGs as well as endothelial dysfunction of arterial grafts.651 653 Compared with nonsmokers, subjects who are smoking at the time of CABG more often have pulmonary complications that require prolonged postopera- tive intubation and a longer ICU stay as well as postoperative infections.654 656 Even smokers who quit just before CABG have fewer postoperative complications than those who continued to smoke.654 As a result, all smokers referred for CABG should be counseled to quit smoking before surgery. Smoking cessation seems to be especially beneficial for patients hospitalized with ACS who then require CABG.644,657 Independent predictors of continued nonsmok- ing 1 year after CABG included 3 previous attempts to quit nonsmoking (OR: 10.0; 95% CI: 2.0 to 50), a definite intention to quit smoking (OR: 12.0; 95% CI: 2.6 to 55.1), and no difficulty with smoking cessation while in the hospital cessation intervention directed at patients early after post- CABG discharge appears to be more effective than a conser- vative approach.642 In a systematic review of 33 trials of smoking cessation, counseling that began during hospitaliza- tion and included supportive contacts for 1 month after hospital discharge increased the rates of smoking cessation (OR: 1.65; 95% CI: 1.44 to 1.90), whereas the use of pharmacotherapy did not improve abstinence rates.643 These findings are supported by a 2009 RCT comparing intensive or minimal smoking cessation intervention in patients hospital- ized for CABG or acute MI.644 In this trial, the 12-month self-reported rate of abstinence was 62% among patients randomly assigned to the intensive program and 46% among those randomly allocated to the minimal intervention (OR: 2.0; 95% CI: 1.2 to 3.1).


Smoking cessation seems to be especially beneficial for patients hospitalized with ACS who then require CABG.644,657 Independent predictors of continued nonsmok- ing 1 year after CABG included 3 previous attempts to quit nonsmoking (OR: 10.0; 95% CI: 2.0 to 50), a definite intention to quit smoking (OR: 12.0; 95% CI: 2.6 to 55.1), and no difficulty with smoking cessation while in the hospital cessation intervention directed at patients early after post- CABG discharge appears to be more effective than a conser- vative approach.642 In a systematic review of 33 trials of smoking cessation, counseling that began during hospitaliza- tion and included supportive contacts for 1 month after hospital discharge increased the rates of smoking cessation (OR: 1.65; 95% CI: 1.44 to 1.90), whereas the use of pharmacotherapy did not improve abstinence rates.643 These findings are supported by a 2009 RCT comparing intensive or minimal smoking cessation intervention in patients hospital- ized for CABG or acute MI.644 In this trial, the 12-month self-reported rate of abstinence was 62% among patients randomly assigned to the intensive program and 46% among those randomly allocated to the minimal intervention (OR: 2.0; 95% CI: 1.2 to 3.1). Overall, a higher rate of continuous abstinence was observed in patients undergoing CABG than in those who had sustained an MI. Interestingly, the rates of abstinence were lower in subjects who used pharmacotherapy regardless of the intervention group (OR: 0.3; 95% CI: 0.2 to Seven first-line pharmacological treatments are available for smoking cessation therapy, including 5 nicotine- replacement therapies; the antidepressant bupropion; and varenicline, a partial agonist of the 4 2 subtype of the nicotinic acetylcholine receptor.659 661 The data supporting the use and timing of nicotine-replacement therapy after CABG are unclear.


Interestingly, the rates of abstinence were lower in subjects who used pharmacotherapy regardless of the intervention group (OR: 0.3; 95% CI: 0.2 to Seven first-line pharmacological treatments are available for smoking cessation therapy, including 5 nicotine- replacement therapies; the antidepressant bupropion; and varenicline, a partial agonist of the 4 2 subtype of the nicotinic acetylcholine receptor.659 661 The data supporting the use and timing of nicotine-replacement therapy after CABG are unclear. One study from a large general practice database reported no increased risk of MI, stroke, or death with nicotine-replacement therapy,662 whereas a retrospective case control study of critically ill patients reported a higher in-hospital mortality rate in those receiving nicotine replace- ment (20% versus 7%; P 0.0085). Despite adjusting for the severity of illness, nicotine-replacement therapy was an independent predictor of inhospital mortality (OR: 24.6; 95% CI: 3.6 to 167.6; P 0.0011).663 Similarly, in a cohort study of post-CABG patients, nicotine-replacement therapy was shown to be an independent predictor of in-hospital mortality after adjusting for baseline characteristics (OR: 6.06; 95% CI: 1.65 to 22.21).663,664 Additional studies are needed to deter- mine the safety of nicotine-replacement therapy in smokers undergoing CABG as well as the optimal time at which to begin such therapy postoperatively. 4.8. Emotional Dysfunction and Psychosocial Considerations: Recommendation Class IIa 1. Cognitive behavior therapy or collaborative care for patients with clinical depression after CABG can be beneficial to reduce objective measures of depres- sion.665 669 (Level of Evidence: B) The negative impact of emotional dysfunction on risk of morbidity and mortality after CABG is well recognized.


Cognitive behavior therapy or collaborative care for patients with clinical depression after CABG can be beneficial to reduce objective measures of depres- sion.665 669 (Level of Evidence: B) The negative impact of emotional dysfunction on risk of morbidity and mortality after CABG is well recognized. In a multivariate analysis of elderly patients after CABG, the 2 most important predictors of death were a lack of social participation and a lack of religious strength.670 Social isola- tion is associated with increased risk of death in patients with CAD,671 and treatment may improve outcomes.672 The most carefully studied mood disorder, depression, occurs com- monly after CABG. Several studies have shown that the primary predictor of depression after CABG is its presence before CABG and that only rarely does CABG cause depres- sion in patients who were not depressed beforehand. In 1 report, half the patients who were depressed before CABG were not depressed afterward, and only 9% of subjects who were not depressed before CABG developed depression postoperatively.673 The prevalence of depression at 1 year after CABG was 33%, which is similar to the prevalence in those undergoing other major operations. Patients with stron- ger perceptions of control of their illness were less likely to be depressed or anxious after CABG.674 No difference in the incidence of mood disturbances was noted when off-pump and on-pump CABG were compared.675 4.8.1. Effects of Mood Disturbance and Anxiety on CABG Outcomes Depression is an important risk factor for the development and progression of CAD.


Effects of Mood Disturbance and Anxiety on CABG Outcomes Depression is an important risk factor for the development and progression of CAD. In fact, it is a more important predictor of the success of cardiac rehabilitation than many other functional cardiac variables.676 Both the presence of depressive symptoms before CABG and the postoperative worsening of these symptoms correlate with poorer physical and psychosocial functioning and poorer quality of life after CABG.677 In a study of 440 patients who underwent CABG, the effects of both preoperative anxiety and depression (as defined by the Depression Anxiety and Stress Scale) on mortality rate were assessed for a median of 5 years postop- eratively.678 Interestingly, preoperative anxiety was associ- ated with a significantly increased risk of death (HR: 1.88; sion was not.678 In a multivariate analysis of 817 patients at Duke University Medical Center, severe depression (assessed using the Center for Epidemiological Studies Depression scale before surgery and 6 months postoperatively665 was associated with increased risk of death (HR: 2.4; 95% CI: 1.4 to 4.0), as was mild or moderate depression that persisted at 6 months (HR: 2.2; 95% CI: 1.2 to 4.2). In another study of 309 subjects followed up for 1 year after CABG, those with diagnostic criteria for a major depressive disorder before discharge were nearly 3 times as likely to have a cardiac event, such as heart failure requiring hospitalization, MI, cardiac arrest, PCI, repeat CABG, or cardiac death.666 Fi- nally, depression after CABG is an important predictor of the recurrence of angina during the first 5 postoperative 4.8.2.


In another study of 309 subjects followed up for 1 year after CABG, those with diagnostic criteria for a major depressive disorder before discharge were nearly 3 times as likely to have a cardiac event, such as heart failure requiring hospitalization, MI, cardiac arrest, PCI, repeat CABG, or cardiac death.666 Fi- nally, depression after CABG is an important predictor of the recurrence of angina during the first 5 postoperative 4.8.2. Interventions to Treat Depression in CABG Patients The Bypassing the Blues investigators identified 302 patients who were depressed before CABG and 2 weeks after dis- charge.668 They were randomly assigned to 8 months of telephone-delivered collaborative care (150 patients) or usual care (152 patients). The 2 groups were compared with each other and also to another group of 151 randomly selected nondepressed post-CABG patients. At 8 month follow-up, the collaborative care group showed an improve- ment in quality of life and physical functioning and were more likely to report a 50% decline in the Hamilton Rating Score for Depression than the usual care group (50.0% versus 29.6%; P 0.001). Men were more likely to benefit from the intervention.668,669 In another study, 123 patients who met the Diagnostic and Statistical Manual of Mental Disorders, 4th edition, criteria for major or minor depression within 1 year of CABG were randomly assigned to 12 weeks of cognitive behavior therapy, 12 weeks of supportive stress management, or usual care.667 Both interventions were efficacious for treating depression after CABG, and cognitive behavior therapy had the most durable effects on depression and several secondary psychological outcome variables.667 Thus, both collaborative intervention and cognitive behavior ther- apy are effective for treating depression in patients after CABG.


Men were more likely to benefit from the intervention.668,669 In another study, 123 patients who met the Diagnostic and Statistical Manual of Mental Disorders, 4th edition, criteria for major or minor depression within 1 year of CABG were randomly assigned to 12 weeks of cognitive behavior therapy, 12 weeks of supportive stress management, or usual care.667 Both interventions were efficacious for treating depression after CABG, and cognitive behavior therapy had the most durable effects on depression and several secondary psychological outcome variables.667 Thus, both collaborative intervention and cognitive behavior ther- apy are effective for treating depression in patients after CABG. Given that depression is associated with adverse outcomes after CABG, it is likely that these interventions also may lead to reduced rates of morbidity and mortality. 4.9. Cardiac Rehabilitation: Recommendation Class I 1. Cardiac rehabilitation is recommended for all eligi- ble patients after CABG.679 681,681a 681d (Level of Evidence: A) See Online Data Supplement 29 for additional data on cardiac rehabilitation. Cardiac rehabilitation, including early ambulation during hospitalization, outpatient prescriptive exercise training, and education, reduces risk of death in survivors of MI.682 684 Beginning 4 to 8 weeks after CABG, 3-times-weekly educa- tion and exercise sessions for 3 months are associated with a Hillis et al 2011 ACCF/AHA CABG Guideline e683 35% increase in exercise tolerance (P 0.0001), a slight (2%) (P 0.05) increase in high-density lipoprotein cholesterol, and a 6% reduction in body fat (P 0.002).421 Exercise training is a valuable adjunct to dietary modification of fat and total caloric intake in maximizing the reduction of body fat while minimizing the reduction of lean body mass.


Cardiac rehabilitation, including early ambulation during hospitalization, outpatient prescriptive exercise training, and education, reduces risk of death in survivors of MI.682 684 Beginning 4 to 8 weeks after CABG, 3-times-weekly educa- tion and exercise sessions for 3 months are associated with a Hillis et al 2011 ACCF/AHA CABG Guideline e683 35% increase in exercise tolerance (P 0.0001), a slight (2%) (P 0.05) increase in high-density lipoprotein cholesterol, and a 6% reduction in body fat (P 0.002).421 Exercise training is a valuable adjunct to dietary modification of fat and total caloric intake in maximizing the reduction of body fat while minimizing the reduction of lean body mass. Aerobic training improves volume of maximum oxygen consumption at 6 months compared with moderate continu- ous training (P 0.001).685 After hospital discharge, CABG patients were randomly assigned to standard care (n 109) or standard care plus rehabilitation (n 119). At 5 years, the groups were similar in symptoms, medication use, exercise capacity, and depression scores, but rehabilitated patients reported better physical mobility, better perceived health, and better perceived overall life situation. A larger proportion of the rehabilitated patients were working at 3 years, although this difference disappeared with longer follow-up.679 Subjects who sustained an MI followed by CABG had greater improvement in exercise tolerance after rehabilitation than did those who had an MI alone. Improvement was sustained for 2 years.686 Observa- tional studies have reported that cardiac events are reduced with rehabilitation after revascularization.680 In many CABG patients, initiation of rehabilitation is a substantial hurdle. Medically indigent patients seem to have rehabilitation compliance and benefit rates similar to those of insured or private-paying patients if rehabilitation is initiated promptly and is structured appropriately.687 In addition to contributing to a patient s sense of well-being, participation in cardiac rehabilitation offers an economic benefit.


Medically indigent patients seem to have rehabilitation compliance and benefit rates similar to those of insured or private-paying patients if rehabilitation is initiated promptly and is structured appropriately.687 In addition to contributing to a patient s sense of well-being, participation in cardiac rehabilitation offers an economic benefit. During a 3-year (mean: 21 months) follow-up after CABG or another coronary event, per capita hospitalization charges were $739 lower for rehabilitated patients compared with nonpartici- pants.688 Post-CABG patients are more likely to resume sexual activity than are survivors of MI. Anticipatory and proactive advice by the physician or surgeon on the safety of resumption of sexual activity as the patient reengages in other daily activities is beneficial.682 Recommendations for intensive risk-reduction therapies for patients with established coronary and other atheroscle- rotic vascular disease are detailed in the AHA/ACC Second- ary Prevention and Risk Reduction Therapy for Patients With Coronary and Other Vascular Disease: 2011 Update. 689 This updated guideline includes recommendations on smoking, blood pressure control, lipid management, physical therapy, weight management, type 2 diabetes management, antiplate- let agents and anticoagulants, renin angiotensin aldosterone system blockers (ACE inhibitors and ARBs), beta blockers, influenza vaccination, depression, and cardiac rehabilitation. 4.10. Perioperative Monitoring Monitoring: Recommendations Class I 1. Continuous monitoring of the electrocardiogram for arrhythmias should be performed for at least 48 hours in all patients after CABG.606,690,691 (Level of Evidence: B) Class IIa 1. Continuous ST-segment monitoring for detection of ischemia is reasonable in the intraoperative period for patients undergoing CABG.53,692 694 (Level of Evidence: B) Class IIb 1. Continuous ST-segment monitoring for detection of is- chemia may be considered in the early postoperative period after CABG.613,690,695 698 (Level of Evidence: B) 4.10.2. Pulmonary Artery Catheterization: Recommendations Class I 1.


Continuous ST-segment monitoring for detection of is- chemia may be considered in the early postoperative period after CABG.613,690,695 698 (Level of Evidence: B) 4.10.2. Pulmonary Artery Catheterization: Recommendations Class I 1. Placement of a pulmonary artery catheter (PAC) is indicated, preferably before the induction of anes- thesia or surgical incision, in patients in cardiogenic shock undergoing CABG. (Level of Evidence: C) Class IIa 1. Placement of a PAC can be useful in the intraoperative or early postoperative period in patients with acute hemo- dynamic instability.699 704 (Level of Evidence: B) Class IIb 1. Placement of a PAC may be reasonable in clinically stable patients undergoing CABG after consider- ation of baseline patient risk, the planned surgical procedure, and the practice setting.699 704 (Level of Evidence: B) 4.10.3. Central Nervous System Monitoring: Recommendations Class IIb 1. The effectiveness of intraoperative monitoring of the processed electroencephalogram to reduce the pos- sibility of adverse recall of clinical events or for detection of cerebral hypoperfusion in CABG pa- tients is uncertain.705 707 (Level of Evidence: B) 2. The effectiveness of routine use of intraoperative or early postoperative monitoring of cerebral oxygen saturation via near-infrared spectroscopy to detect cerebral hypoperfusion in patients undergoing CABG is uncertain.708 710 (Level of Evidence: B) See Online Data Supplement 30 for additional data on central nervous system monitoring. Requirements for basic perioperative monitoring in pa- tients undergoing CABG, including heart rate, blood pres- sure, peripheral oxygen saturation, and body temperature, are well accepted.


Requirements for basic perioperative monitoring in pa- tients undergoing CABG, including heart rate, blood pres- sure, peripheral oxygen saturation, and body temperature, are well accepted. Additional intraoperative standards established by the American Society of Anesthesiologists, including the addition of end-tidal carbon dioxide measurement in the intubated patient, are uniformly applied.711 Specialized mon- itoring of cardiac and cerebral function varies among centers and includes the use of PACs, TEE, or other forms of echocardiography (Section 2.1.7); noninvasive monitors of cardiac output; processed electroencephalographic monitor- ing; and cerebral oximetry with near-infrared spectroscopy. Given the added expense and potential hazards of such monitors (eg, pulmonary artery rupture with PAC, false- positive changes with cerebral oximetry or processed electro- encephalogram), substantial controversy exists about indica- tions for their use. None of these monitoring methods is routinely recommended. Electrocardiographic monitoring includes an assessment of heart rate and rhythm as well as the morphology and deviation of the QRS complex and ST segments for evidence of ischemia, infarction, or abnormal conduction.690 Continu- ous telemetric monitoring of cardiac rate and rhythm is recommended for 48 to 72 hours after surgery in all patients because of the high incidence of post-CABG AF, which most often occurs 2 and 4 days after surgery.606,613,690,691,697,698 In addition, other arrhythmias and conduction abnormalities may occur in patients with ischemia because of incomplete revascularization or in those undergoing concurrent valve replacement. Uncertainty continues with regard to the utility of PAC in low-risk patients undergoing CABG.712 Several observational studies suggest that such patients can be managed only with monitoring of central venous pressure, with insertion of a PAC held in reserve should the need arise.


Uncertainty continues with regard to the utility of PAC in low-risk patients undergoing CABG.712 Several observational studies suggest that such patients can be managed only with monitoring of central venous pressure, with insertion of a PAC held in reserve should the need arise. In fact, it has even been suggested that patients in whom a PAC is placed incur greater resource utilization and more aggressive therapy, which may lead to worse outcomes and higher costs. The reported rates of PAC use range from 10% in a combined private academic setting to 90% in patients in the Depart- ment of Veterans Affairs health system.61,639,701,702,713 Aside from providing an indirect assessment of left atrial pressure and the presence and severity of pulmonary hyper- tension, PAC can be used to measure cardiac output (by thermodilution) and to monitor the mixed venous oxygen saturation information that may be helpful in the manage- ment of high-risk patients.712,714 The need for careful consid- eration of baseline patient risk, the planned procedure, and the patient setting before use of a PAC are outlined in several opinion pieces, consensus documents, the Practice Guide- lines for Pulmonary Artery Catheterization: An Updated Report by the American Society of Anesthesiologists, and the 2009 ACCF/AHA Focused Update on Perioperative Beta Blockade Incorporated Into the ACC/AHA 2007 Guide- lines on Perioperative Cardiovascular Evaluation and Care for Noncardiac Surgery. 699,712,714 716 Pulmonary artery per- foration or rupture is fatal in 50% of patients in whom it occurs.


699,712,714 716 Pulmonary artery per- foration or rupture is fatal in 50% of patients in whom it occurs. This complication usually can be avoided by 1) withdrawal of the catheter tip into the main pulmonary artery before initiation of CPB; 2) withdrawal of the catheter into the pulmonary artery before balloon inflation, especially if the pressure tracing suggests damping; and 3) avoiding routine measurement of the pulmonary artery wedge pressure, reserving this maneuver as a specific diagnostic event. Perioperative monitoring of cerebral function (primarily with an electroencephalogram) has been used in certain high-risk patients, such as those undergoing neurosurgery or carotid vascular surgery.717 In the setting of cardiac surgery, the potentially deleterious effects of CPB on cerebral hypop- fusion or embolic events (ie, air or aortic calcific debris) have been investigated via transcranial Doppler techniques, with a lesser emphasis on the electroencephalogram (in part because of excessive artifact in this setting).57,718 Although processed electroencephalographic monitors and bifrontal cerebral oxi- metry have been available for more than 2 decades, contro- versy remains about their clinical effectiveness.719,720 Pro- cessed electroencephalographic monitoring is aimed primarily at assessing the risk of conscious recall of intraop- erative events, but it also has been used to gauge the depth of anesthesia, theoretically allowing more precise titration of the anesthetic.721,722 Although a variety of electroencephalo- graphic variables are commonly accepted as markers of cerebral ischemia, the ability of current commercial devices to detect or quantify ischemia is limited.706,707,717,718 Given the intuitive link between reflectance oximetry (ie, for peripheral oxygen or mixed venous oxygen saturation) and clinical interventions (ie, manipulating hemodynamic variables, the fraction of inspired oxygen, etc.)


Perioperative monitoring of cerebral function (primarily with an electroencephalogram) has been used in certain high-risk patients, such as those undergoing neurosurgery or carotid vascular surgery.717 In the setting of cardiac surgery, the potentially deleterious effects of CPB on cerebral hypop- fusion or embolic events (ie, air or aortic calcific debris) have been investigated via transcranial Doppler techniques, with a lesser emphasis on the electroencephalogram (in part because of excessive artifact in this setting).57,718 Although processed electroencephalographic monitors and bifrontal cerebral oxi- metry have been available for more than 2 decades, contro- versy remains about their clinical effectiveness.719,720 Pro- cessed electroencephalographic monitoring is aimed primarily at assessing the risk of conscious recall of intraop- erative events, but it also has been used to gauge the depth of anesthesia, theoretically allowing more precise titration of the anesthetic.721,722 Although a variety of electroencephalo- graphic variables are commonly accepted as markers of cerebral ischemia, the ability of current commercial devices to detect or quantify ischemia is limited.706,707,717,718 Given the intuitive link between reflectance oximetry (ie, for peripheral oxygen or mixed venous oxygen saturation) and clinical interventions (ie, manipulating hemodynamic variables, the fraction of inspired oxygen, etc.), there is considerable interest in the use of bifrontal cerebral oximetry as a measure of brain perfusion.723 Two RCTs in CABG patients suggest that bifrontal cerebral oximetry may be helpful in predicting early perioperative cognitive decline, stroke, noncerebral complications, and ICU and hospital length of stay.709,710 A 2011 observational cohort (1178 CABG patients) suggested that a patient s preoperative re- sponse to breathing oxygen for 2 minutes (ScO2 50%) is an independent predictor of death at 30 days and 1 year after 5.


, there is considerable interest in the use of bifrontal cerebral oximetry as a measure of brain perfusion.723 Two RCTs in CABG patients suggest that bifrontal cerebral oximetry may be helpful in predicting early perioperative cognitive decline, stroke, noncerebral complications, and ICU and hospital length of stay.709,710 A 2011 observational cohort (1178 CABG patients) suggested that a patient s preoperative re- sponse to breathing oxygen for 2 minutes (ScO2 50%) is an independent predictor of death at 30 days and 1 year after 5. CABG-Associated Morbidity and Mortality: Occurrence and Prevention Several comprehensive data registries for CABG have been developed in the United States, the largest being the STS Adult Cardiac Database. For 20 years, these registries have collected data on all aspects of the procedure.306,725,727 A detailed analysis of these data and their correlation to out- comes has facilitated the creation of risk-assessment models that estimate the rates at which various adverse events occur. On the basis of these models, risk-adjusted outcomes for hospitals and surgeons have been calculated and, in some instances, publicly reported. 5.1. Public Reporting of Cardiac Surgery Outcomes: Recommendation Class I 1. Public reporting of cardiac surgery outcomes should use risk-adjusted results based on clinical data.728 735 (Level of Evidence: B) See Online Data Supplement 31 for additional data on public reporting of cardiac surgery outcomes.


Public reporting of cardiac surgery outcomes should use risk-adjusted results based on clinical data.728 735 (Level of Evidence: B) See Online Data Supplement 31 for additional data on public reporting of cardiac surgery outcomes. To address the need for valid and reliable risk-adjusted outcomes data, cardiac surgery registries were developed by the STS,306,725,727 Veterans Administration,306,736 738 North- ern New England Cardiovascular Disease Study Group,739,740 and the state of New York.741,742 These have been the basis for several performance assessment and improvement strate- gies, including public report cards,742 744 confidential feed- back to participants showing their performance relative to national benchmarks,306,737,745 748 and state or regional col- Hillis et al 2011 ACCF/AHA CABG Guideline e685 laboratives that identify and disseminate best-practices infor- mation.749 Public report cards are the most controversial of these 3 approaches. Although they provide transparency and public accountability, it is unclear if they are the only or best way to improve quality. Reductions in the CABG mortality rate after the publication of such report cards in New York were encour- aging,742,750 752 but subsequent studies revealed comparable reductions in other states, regions, and countries that used confidential feedback with or without performance improvement initiatives.752 754 These findings suggest that the common de- nominator among successful performance improvement strate- gies is the implementation of a formal quality assessment and feedback program benchmarked against regional or national results.755 The incremental value of public (as opposed to confidential) reporting is controversial.


Reductions in the CABG mortality rate after the publication of such report cards in New York were encour- aging,742,750 752 but subsequent studies revealed comparable reductions in other states, regions, and countries that used confidential feedback with or without performance improvement initiatives.752 754 These findings suggest that the common de- nominator among successful performance improvement strate- gies is the implementation of a formal quality assessment and feedback program benchmarked against regional or national results.755 The incremental value of public (as opposed to confidential) reporting is controversial. Although providers fear the potential negative impact of public reporting on referrals and market share, this concern seems to be unfounded.756 765 Even when such impact has been observed, it has generally been modest, transient, and limited to areas populated by more affluent and educated subjects.760 762,766 With implementation of healthcare reform legislation that increases access of consumers and payers to objective data and more easily understood data presentations, the influence of public report cards is likely to increase in the future.762,767 771 As this occurs, it will be important to monitor unintended negative consequences, such as gaming of the reporting system772 and avoidance of high-risk patients (risk aversion), the precise group of patients who are most likely to benefit from aggressive intervention.773 776 Methodological considerations are important for provider profiling and public reporting. Numerous studies have shown the superiority of clinical over administrative data for these purposes.728 731,733,734 The latter data lack critical clinical variables that are necessary for adequate risk adjust- ment,732,735 they may confuse comorbidities and complica- tions, and they may contain inaccurate case numbers and mortality rates.


Numerous studies have shown the superiority of clinical over administrative data for these purposes.728 731,733,734 The latter data lack critical clinical variables that are necessary for adequate risk adjust- ment,732,735 they may confuse comorbidities and complica- tions, and they may contain inaccurate case numbers and mortality rates. Outcomes measures, such as mortality, should always be adjusted for patient severity on admission (ie, risk-adjusted or risk-standardized )777 780; otherwise, pro- viders will be hesitant to care for severely ill patients, who are more likely to die from their disease. In addition, if a hospital or surgeon is found to be a low-performing outlier on the basis of unadjusted results, the hospital or surgeon may claim that their patients were sicker. Statistical methodologies should account for small sample sizes and clustered patient observations within institutions, and hierarchical or random- effects models have been advocated by some investiga- tors.743,781 787 Point estimates of outcomes should always be accompanied by measures of statistical uncertainty, such as CIs. The units of analysis and reporting for provider profiling also have implications. Surgeon-level reports are published together with hospital reports in several states, but their smaller sample sizes typically require data aggregation over several years. Surgeon-level reporting may also increase the potential for risk aversion, as the anticipated worse results of the highest-risk patients are not diluted by the larger volume of a hospital or group.


Surgeon-level reporting may also increase the potential for risk aversion, as the anticipated worse results of the highest-risk patients are not diluted by the larger volume of a hospital or group. Finally, because the distribution of patient severity may vary substantially among providers, direct comparison of the results of one surgeon or hospital with those of another, even by using indirectly risk- standardized results, is often inappropriate.788 Rather, these results should be interpreted as comparisons of a provider s outcomes for his or her specific patient cohort versus what would have been expected had those patients been cared for by an average provider in the benchmark population. Although risk-adjusted mortality rate has been the domi- nant performance metric in cardiac surgery for 2 decades, other more comprehensive approaches have been advo- cated.789 The STS CABG composite illustrates one such multidimensional approach, consisting of 11 National Quality Forum endorsed measures of cardiothoracic surgery perfor- mance grouped within 4 domains of care.619,790 5.1.1. Use of Outcomes or Volume as CABG Quality Measures: Recommendations Class I 1. All cardiac surgery programs should participate in a state, regional, or national clinical data registry and should receive periodic reports of their risk-adjusted outcomes. (Level of Evidence: C) Class IIa 1. When credible risk-adjusted outcomes data are not available, volume can be useful as a structural metric of CABG quality.309,751,791 798,800 804,807,818 (Level of Evidence: B) Class IIb 1. Affiliation with a high-volume tertiary center might be considered by cardiac surgery programs that perform fewer than 125 CABG procedures annually. (Level of Evidence: C) See Online Data Supplement 32 for additional data on outcomes or volume as CABG quality measures.


(Level of Evidence: C) See Online Data Supplement 32 for additional data on outcomes or volume as CABG quality measures. Numerous studies have demonstrated an association be- tween hospital or individual practitioner volume and outcome for a variety of surgical procedures and some medical conditions.805 831 CABG was one of the original procedures for which this volume outcome association was investi- gated.309,751,791 798,800 804,807,818 The CABG volume outcome association is generally weaker than that of other procedures, such as esophagectomy or pancreatectomy, which are per- formed less often. In addition, the results of volume outcome studies vary substantially according to methodology. The apparent strength of the volume outcome association often diminishes with proper risk adjustment based on clinical (as opposed to administrative) data.802,808 It is also weaker in more contemporary studies, presumably because of improved techniques and increasing experience.795,802 Finally, volume outcome associations appear weaker when hierarchical mod- els are used that properly account for small sample sizes and clustering of observations.832 The impact of CABG volume was studied in an observational cohort of 144 526 patients from 733 hospitals that participated in the STS Adult Cardiac Surgery Database in 2007.309 In this analysis, a weak associ- ation between volume and unadjusted mortality rate was noted (2.6% unadjusted mortality rate for hospitals perform- ing 100 procedures versus 1.7% for hospitals performing 450 procedures).309 Using multivariate hierarchical regres- sion, the largest OR (1.49) was found for the lowest-volume ( 100 cases) group versus the highest-volume group. Desir- able processes of care (except for use of the IMA) and morbidity rates were not associated with volume.


Desir- able processes of care (except for use of the IMA) and morbidity rates were not associated with volume. The average STS-CABG composite score for the lowest-volume group ( 100 cases per year) was significantly lower than that of the 2 highest-volume groups, but volume explained only 1% of variation in the composite score.619,790 In general, the best results are achieved most consistently by high-volume surgeons in high-volume hospitals and the worst results by low-volume surgeons in low-volume hospi- tals.793,794 However, many low-volume programs achieve excellent results, perhaps related to appropriate case selec- tion; effective teamwork among surgeons, nurses, anesthesi- ologists, perfusionists, and physician assistants; and adoption of best practices derived from larger programs.833,834 As a quality assessment strategy, participation in a state, regional, or national clinical data registry that provides regular performance feedback reports is highly recommended for all cardiac programs. Random sampling variation is greater at low volumes,309,797,798,803,827,834,835 which compli- cates performance assessment of smaller programs.


Random sampling variation is greater at low volumes,309,797,798,803,827,834,835 which compli- cates performance assessment of smaller programs. Several strategies may be considered to mitigate this measurement issue, including analysis over longer periods of time; appro- priate statistical methodologies, such as hierarchical (random- effects) models; composite measures, which effectively in- crease the number of endpoints; and statistical quality control approaches, such as funnel plots835 and cumulative sum plots.836 838 Small programs may benefit from direct super- vision by a large tertiary center.834 Ultimately, state or national regulatory authorities must decide whether the lower average performance of very small programs and the added difficulty in accurately measuring their performance are outweighed by other considerations, such as the need to maintain cardiac surgery capabilities in rural areas with limited access to referral centers.834 Volume, a structural quality metric, is an imperfect proxy for direct measurement of outcomes.822,839 Risk- adjusted outcomes based on clinical data are the preferred method of assessing CABG quality except in very low- volume programs, in which performance is generally weakest and small sample size makes accurate assessment of performance difficult. 5.2. Adverse Events 5.2.1. Adverse Cerebral Outcomes The incidence of stroke after CABG ranges from 1.4% to 3.8%,840 depending on the patient population and the criteria for diagnosis of stroke. Risk factors for stroke include advanced age, history of stroke, diabetes mellitus, hyperten- sion,841 and female sex,842 with newer research emphasizing the importance of preoperative atherosclerotic disease (in- cluding radiographic evidence of previous stroke or aortic atheromatous disease).843 Although macroembolization and microembolization are major sources of stroke, hypoperfu- sion,844 perhaps in conjunction with embolization,845 is a risk factor for postoperative stroke.


Risk factors for stroke include advanced age, history of stroke, diabetes mellitus, hyperten- sion,841 and female sex,842 with newer research emphasizing the importance of preoperative atherosclerotic disease (in- cluding radiographic evidence of previous stroke or aortic atheromatous disease).843 Although macroembolization and microembolization are major sources of stroke, hypoperfu- sion,844 perhaps in conjunction with embolization,845 is a risk factor for postoperative stroke. The mortality rate is 10-fold higher among post-CABG patients with stroke than among those without it, and lengths of stay are longer in stroke Although off-pump CABG was introduced in large part to reduce stroke and other adverse neurological outcomes asso- ciated with CPB, several RCTs comparing on-pump and off-pump CABG have shown no difference in stroke See Online Data Supplement 33 for additional data on stroke rates. 5.2.1.1.1. Use of Epiaortic Ultrasound Imaging to Reduce Stroke Rates: Recommendation Class IIa 1. Routine epiaortic ultrasound scanning is reasonable to evaluate the presence, location, and severity of plaque in the ascending aorta to reduce the incidence of atheroembolic complications.847 849 (Level of Evi- dence: B) Identification of an atherosclerotic aorta is believed to be an important step in reducing the risk of stroke after CABG.850 Intraoperative assessment of the ascending aorta for detection of plaque by epiaortic ultrasound imaging is superior to direct palpation and TEE.851,852 Predictors of ascending aortic atherosclerosis include increasing age, hypertension, extracardiac atherosclerosis (peripheral ar- tery and cerebrovascular disease), and elevated serum creatinine concentrations.853 855 Prospective RCTs to eval- uate the role of epiaortic scanning in assessing stroke risk have not been reported, but several observational studies reported stroke rates of 0 to 1.4%847 849,853,856,857 when surgical decision making was guided by the results of epiaortic scanning.