Relationship of extent of revascularization with angina at one year in the Bypass Angioplasty Revascularization Investigation (BARI)

The Complementary Value of Absolute Coronary Flow in the Assessment of Patients with Ischaemic Heart Disease

Fractional flow reserve (FFR) is the current gold-standard invasive assessment of coronary artery disease (CAD). FFR reports coronary blood flow (CBF) as a fraction of a hypothetical and unknown normal value. Although used routinely to diagnose CAD and guide treatment, how accurately FFR predicts actual CBF changes remains unknown. Here we compared fractional CBF with the absolute CBF (aCBF in mL/min), measured with a computational method during standard angiography and pressure-wire assessment, on 203 diseased arteries (143 patients). We found a substantial correlation between the two measurements (r 0.89, Cohen’s Kappa 0.71). Concordance between fractional and absolute CBF reduction was high when FFR was >0.80 (91%), but reduced when FFR was ≤0.80 (81%), 0.70-0.80 (68%) and, particularly 0.75-0.80 (62%). Discordance was associated with coronary microvascular resistance, vessel diameter and mass of myocardium subtended, all factors to which FFR is agnostic. Assessment of aCBF complements FFR, and may be valuable to assess CBF, particularly in cases within the FFR ‘grey-zone’.

Role of surgical revascularization in diabetic patients with coronary artery disease

Diabetes is a well-known risk factor for morbidity and mortality associated with coronary artery disease. Currently, diabetics represent approximately a quarter of patients requiring coronary revascularization in the USA. The purpose of this article is to review and analyze the available data in surgical revascularization of diabetic patients with coronary artery disease. The review will also examine new developments in myocardial revascularization and assess their probable impact on the long-term outcome of diabetic patients.

Clinical outcome of arterial myocardial revascularization using bilateral internal thoracic arteries in diabetic patients: a single centre experience

OBJECTIVES

The use of bilateral internal thoracic arteries (BITAs) grafting has been documented to be advantageous over left internal thoracic artery (LITA) grafting. It has been shown to significantly improve clinical outcomes and increase long-term survival in patients with diabetes. However, harvesting BITAs may result in a greater risk of superficial wound infection (SWI) or deep sternal wound infection (DSWI) and cardiovascular complications (major adverse cardiac and cerebrovascular events; MACCE) in such a patient group. The objective of this study was to compare the incidence of SWI or DSWI and cardiovascular events in a series of isolated coronary artery bypass grafting (CABG) patients who underwent BITA grafting vs LITA grafting.

METHODS

A total of 147 patients with coronary artery disease and diabetes underwent isolated CABG at John Paul II Hospital. Of these, 38 procedures were performed using BITA grafting and 109 with LITA-saphenous vein grafting.

RESULTS

MACCE were similar in bilateral groups (7.9%--BITA group and 9.2%--LITA group). No significant difference was found in mortality and length of stay between bilateral groups. The MACCE risk factor was age. The incidence of SWI and DSWI and sternal re-fixation did not differ between the BITA or LITA groups (5.2 vs 9.1%, 5.2 vs 7.3% and 5.2 vs 6.4%). The risk factors for DSWI were age (odds ratio 3.47, P = 0.032 for every 10 years) and body mass index >30 kg/m(2).

CONCLUSIONS

Perioperative complications do not increase with the use of BITAs in this group of diabetic patients. There are no statistically significant differences in the number of superficial or deep wound infections or number of sternal resuturing between the BITA and LITA groups.

Do differences in repeat revascularization explain the antianginal benefits of bypass surgery versus percutaneous coronary intervention?: implications for future treatment comparisons

BACKGROUND

Patients with multivessel coronary disease treated with coronary artery bypass graft (CABG) have less angina than those treated with percutaneous coronary intervention (PCI); however, there is uncertainty as to the mechanism of greater angina relief with CABG and whether more frequent repeat revascularization in patients treated with PCI could account for this treatment difference.

METHODS AND RESULTS

In the Synergy between percutaneous coronary intervention (PCI) with TAXUS and Cardiac Surgery trial, 1800 patients with 3-vessel or left main coronary artery disease were randomized to CABG or PCI with paclitaxel-eluting stents. Health status was assessed at baseline, 1, 6, and 12 months, using the Seattle Angina Questionnaire and the Medical Outcomes Study Short Form General Health Survey, and the association between repeat revascularization and health status during follow-up was assessed using longitudinal models. In adjusted analyses, patients who underwent repeat revascularization had worse angina frequency scores than patients who did not in both treatment groups, with differences of 8.5 points at 6 months and 3.1 points at 12 months in patients treated with PCI and 19.8 points at 6 months and 11.2 points at 12 months in patients with patients treated with CABG. Among patients who did not require repeat revascularization, the adjusted effect of CABG versus PCI on 12-month angina frequency scores was nearly identical to the overall benefit in the intention-to-treat analysis.

CONCLUSIONS

Among patients with multivessel coronary artery disease treated with PCI or CABG, the occurrence of repeat revascularization during follow-up did not fully explain the antianginal benefit of CABG in the overall population. The differential association between repeat revascularization and anginal status, according to the type of initial revascularization procedure, suggests that this end point should play a limited role in any direct comparison of the 2 treatment strategies.

Impact of completeness of revascularization on long-term cardiovascular outcomes in patients with type 2 diabetes mellitus: results from the Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D)

BACKGROUND

Patients with diabetes have more extensive coronary disease than those without diabetes, resulting in more challenging percutaneous coronary intervention or surgical (coronary artery bypass graft) revascularization and more residual jeopardized myocardium. The Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) trial provided an opportunity to examine the long-term clinical impact of completeness of revascularization in patients with diabetes.

METHODS AND RESULTS

This is a post hoc, nonrandomized analysis of the completeness of revascularization in 751 patients who were randomly assigned to early revascularization, of whom 264 underwent coronary artery bypass graft surgery and 487 underwent percutaneous coronary intervention. The completeness of revascularization was determined by the residual postprocedure myocardial jeopardy index (RMJI). RMJI is a ratio of the number of myocardial territories supplied by a significantly diseased epicardial coronary artery or branch that was not successfully revascularized, divided by the total number of myocardial territories. Mean follow-up for mortality was 5.3 years. Complete revascularization (RMJI=0) was achieved in 37.9% of patients, mildly incomplete revascularization (RMJI >0≤33) in 46.6%, and moderately to severely incomplete revascularization (RMJI >33) in 15.4%. Adjusted event-free survival was higher in patients with more complete revascularization (hazard ratio, 1.14; P=0.0018).

CONCLUSIONS

Patients with type 2 diabetes mellitus and less complete revascularization had more long-term cardiovascular events.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00006305.

Completeness of revascularization and survival among octogenarians with triple-vessel disease

BACKGROUND

We sought to determine the impact of the completeness of surgical revascularization among octogenarians with triple-vessel disease.

METHODS

Between 1992 and 2008, 476 consecutive patients aged 80 years or more who underwent primary isolated coronary artery bypass grafting (CABG) procedures were identified. Early and late survival were compared among patients who underwent complete revascularization (CR, n=391) and incomplete revascularization (IR, n=85). IR was present when 1 or more of the 3 main coronary arteries with 50% or greater stenosis that were identified preoperatively as a surgical target by the operating surgeon were not grafted. The mean follow-up was 5.4±3.0 years (maximum 15.3 years).

RESULTS

Baseline risk was similar between the 2 groups of patients. IR was more frequent in off-pump compared with on-pump CABG (34.9% versus 16.2%, respectively; p=0.002). The most common reason for IR was small or severely diseased arteries (87%). The incidence of postoperative myocardial infarction (MI) was similar in both groups (CR, 18.4% versus IR, 17.3%; p=0.81). In-hospital mortality was 7.2% among patients with CR and 4.7% among patients with IR (p=0.60). Three, 5-, and 8-year freedom from all-cause mortality among patients who underwent CR were 89.2%, 74.1%, and 54.3%, respectively, and were not significantly different from those patients who underwent IR (86.6%, 74.5%, and 49.4%, respectively) (p=0.40).

CONCLUSIONS

In octogenarians with triple-vessel disease, a strategy of incomplete revascularization during CABG does not negatively impact early or long-term survival.

Various clinical scenarios leading to development of the string sign of the internal thoracic artery after coronary bypass surgery: the role of competitive flow, a case series

Background

The left internal mammary artery (LIMA) is the choice for grafting of the left anterior descending coronary artery (LAD). One possible mechanism of the rare graft failure involve the presence of competitive flow.

Method

105 patients who had undergone coronary bypass grafting between 1998 and 2000 were included in this observational study. The recatheterizations were performed 28 months after the operations. The rate of patency the LIMA grafts was determined, and the cases with graft failure were analyzed.

Results

The LIMA graft was patent in 99 patients (94%). Six patients (6%) exhibited diffuse involution of the graft (string sign). The string sign was always associated with competitive flow as the basis of the LIMA graft involution. In one case quantitative re-evaluation of the preoperative coronary angiography revealed merely less than 50% diameter stenosis on the LAD with a nonligated side-branch of the LIMA. At recatheterization in two patients the pressure wire measurements demonstrated only a non-significant decrease of the fractional flow reserve (0.83 and 0.89), despite the 53% and 57% diameter stenosis in the angiogram. Another patient displayeda significant regression of the LAD lesion between the pre- and postoperative coronary angiography (from 76% to 44%) as the cause of the development of the competitive flow. In one instance, a radial artery graft on the LAD during a redo bypass operation resulted in competitive flow in the radial graft due to the greater diameter than that of the LIMA. In a further patient, competitive flow developed from a short sequential part of the LIMA graft between the nonsignificantly stenosed diagonal branch and the LAD, with involution of the main part of the graft to the diagonal branch.

Conclusions

The most common cause of the development of the string sign of a LIMA graft due to competitive flow is overassessment of the lesion of the LAD. Regression of a previous lesion or some other neighboring graft can also cause the phenomenon.

Myocardial revascularization by coronary arterial bypass graft: past, present, and future

The history of coronary artery bypass graft surgery is an amazing story that evolved from a basic understanding of the etiology of coronary artery disease to highly sophisticated methods of restoring blood flow to the myocardium. Adjunctive techniques of anticoagulation, coronary artery imaging, and cardiopulmonary bypass contributed greatly to our ability to provide surgical revascularization. Today, coronary artery bypass graft surgery is the treatment of choice for many patients with complex coronary artery disease. The future will certainly bring improved results with better graft patency with less operative insult and morbidity as the final chapter in the story remains untold.

Surgical, medical, and percutaneous therapies for patients with multivessel coronary artery disease

Patients with multivessel coronary artery disease (CAD) are now faced with a number of treatment choices, including coronary artery bypass graft surgery, medical therapy, and percutaneous coronary interventions (using bare-metal or drug-eluting stents). Each carries certain benefits and risks: bypass surgery is favored in the subset of patients with multivessel disease and diabetes or impaired left ventricular systolic function who are able to receive a left internal mammary artery graft; medical therapy consisting of beta-blockers, angiotensin-converting enzyme inhibitors, statins, aspirin, and nitrates is offered to patients with stable angina. Percutaneous procedures have previously been limited in their efficacy by restenosis and resulting morbidity, but contemporary stenting procedures appear to show equivalent mortality and morbidity outcomes (to bypass surgery) at 5 years. Drug-eluting stents are the newest percutaneous technique and show significant reduction in restenosis compared with older catheter-based therapies, but further investigation is needed to definitively define the role of drug-eluting stents in the treatment of multivessel CAD. This review summarizes the data comparing medical, surgical, and percutaneous treatment approaches for patients with multivessel CAD.

Native coronary disease progression exceeds failed revascularization as cause of angina after five years in the bypass angioplasty revascularization investigation (BARI)

OBJECTIVES

Coronary angiograms obtained five years following revascularization were examined to assess the extent of compromise in myocardial perfusion due to failure of revascularization versus progression of native disease.

BACKGROUND

The Bypass Angioplasty Revascularization Investigation (BARI) randomized revascularization candidates between bypass surgery and angioplasty. Entry and five-year angiograms from 407 of 519 (78%) patients at four centers were analyzed.

METHODS

Analysis of the distribution of coronary vessels and stenoses provided a measure of myocardial jeopardy that correlates with presence of angina. The extent to which initial benefits of revascularization were undone by failed revascularization versus native disease progression was assessed.

RESULTS

Myocardial jeopardy fell following initial revascularization, from 60% to 17% for percutaneous coronary intervention (PCI)-treated patients compared with 60% to 7% for coronary artery bypass graft (CABG) surgery patients (p < 0.001), rebounding at five years to 25% for PCI and 20% for surgery patients (p = 0.01). Correspondingly, angina prevalence was higher at five years in PCI-treated patients than in surgery-treated patients (28% vs. 18%; p = 0.03). However, myocardial jeopardy at five years, and not initial treatment (PCI vs. surgery), was independently associated with late angina. Increased myocardial jeopardy from entry to five-year angiogram occurred in 42% of PCI-treated patients and 51% of CABG-treated patients (p = 0.06). Among the increases in myocardial jeopardy, two-thirds occurred in previously untreated arteries.

CONCLUSIONS

Native coronary disease progression occurred more often than failed revascularization in both PCI- and CABG-treated patients as a cause of jeopardized myocardium and angina recurrence. These results support intensive postrevascularization risk-factor modification.

Poor functional recovery may indicate restenosis in patients after coronary angioplasty

OBJECTIVE

To investigate whether poor response to exercise training can detect restenosis in asymptomatic patients after percutaneous transluminal coronary angioplasty (PTCA).

DESIGN

Case-control study.

SETTING

A hospital-based outpatient cardiac rehabilitation program in Taiwan.

PARTICIPANTS

Sixteen patients aged 49.7+/-7.8 years who had undergone PTCA and completed a 3-month exercise program. Patients were separated into a restenosis group (n=7; age, 46.4+/-9.8y) and a nonrestenosis group (n=9; age, 52.3+/-12.9y), according to their angiography follow-up results. The interval between PTCA and angiography ranged from 6 months to 2 years.

INTERVENTION

Bicycle exercise workouts were conducted 3 times a week during rehabilitation, with exercise intensity adjusted to each patient's ventilatory threshold.

MAIN OUTCOME MEASURES

A graded exercise test with gas analysis was conducted before training, at 6 weeks and at 3 months after training, to evaluate the sequential changes of cardiorespiratory function.

RESULTS

After 3 months of training, the nonrestenosis group showed an increase of 30.4% in peak oxygen uptake (Vo(2)peak, P<.05), 13.7% in peak oxygen pulse (P<.05), 22.2% in peak rate-pressure product (P<.05), and 13.6% in peak work rate (P<.05). Most of the improvement occurred within the first 6 weeks of training. The restenosis group did not show significant increase in these variables. At the ventilatory threshold, the nonrestenosis group also displayed a significant increase of Vdot;o(2), oxygen pulse, and work rate. However, the restenosis group showed no improvement after training.

CONCLUSION

Functional recovery appears to be a good indicator of restenosis for patients after PTCA. A poor response to exercise can be noted within 6 weeks of training in PTCA patients with restenosis.

Coronary bypass graft patency in patients with diabetes in the Bypass Angioplasty Revascularization Investigation (BARI)

BACKGROUND

Few studies have compared long-term status of bypass grafts between patients with and without diabetes, and uncertainty exists as to whether diabetes independently predicts poor clinical outcome after CABG.

METHODS AND RESULTS

Among 1526 patients in BARI who underwent CABG as initial revascularization, 99 of 292 (34%) with treated diabetes mellitus (TDM) (those on insulin or oral hypoglycemic agents) and 469 of 1234 (38%) without TDM had follow-up angiography. Angiograms with the longest interval from initial surgery and before any percutaneous graft intervention (mean 3.9 years) were reviewed. An average of 3.0 grafts were placed at initial CABG for patients with TDM (n=297; internal mammary artery [IMA], 33%) and 2.9 grafts for patients without TDM (n=1347; IMA, 34%). Patients with TDM were more likely than those without to have small (<1.5 mm) grafted distal vessels (29% versus 22%) and vessels of poor quality (9% versus 6%). On follow-up angiography, 89% of IMA grafts were free of stenoses > or =50% among patients with TDM versus 85% among patients without TDM (P=0.23). For vein grafts, the corresponding percentages were 71% versus 75% (P=0.40). After statistical adjustment, TDM was unrelated to having a graft stenosis > or =50% (adjusted odds ratio, 0.87; 95% CI, 0.58 to 1.32).

CONCLUSIONS

Despite diabetic patients' having smaller distal vessels and vessels judged to be of poorer quality, diabetes does not appear to adversely affect patency of IMA or vein grafts over an average of 4-year follow-up. Previously observed differences in survival between CABG-treated patients with and without diabetes may be largely a result of differential risk of mortality from noncardiac causes.

Improvement of cardiorespiratory function after percutaneous transluminal coronary angioplasty or coronary artery bypass grafting

OBJECTIVE

The objective of this study was to investigate the effect of a 3-mo training program for patients with either a percutaneous transluminal coronary angioplasty (PTCA) or a coronary artery bypass grafting (CABG).

DESIGN

Forty-four patients participated in a 3-mo outpatient cardiac rehabilitation program. Graded exercise tests with gas analysis were conducted before and after training to evaluate the changes of cardiorespiratory function.

RESULTS

In the pretraining examination, the PTCA group showed a higher peak oxygen uptake (VO2peak) and work rate than the CABG group. In the posttraining examination, the PTCA group increased 14.6% in VO2peak. Meanwhile, the CABG group increased 32.8% in VO2peak. At the ventilatory threshold, both groups also significantly increased in Vo2.

CONCLUSIONS

A 3-mo cardiac rehabilitation program for patients with PTCA or CABG could favorably enhance their cardiorespiratory function. Although the pretraining VO2peak was lower for the patients with CABG, their training potential was greater, and hence they could achieve a similar level of aerobic capacity as the PTCA group.

Differential influence of diabetes mellitus on increased jeopardized myocardium after initial angioplasty or bypass surgery: bypass angioplasty revascularization investigation

BACKGROUND

Data are absent that compare midterm angiographic outcome between patients with and without diabetes after initial percutaneous transluminal coronary angioplasty (PTCA) and coronary artery bypass graft surgery (CABG). Importantly, diabetes mellitus may differentially influence long-term survival after PTCA or CABG.

METHODS AND RESULTS

Patients with multivessel coronary disease who were previously enrolled in the Bypass Angiopathy Revascularization Investigation to compare initial PTCA versus CABG (n=1829) and who had a reduction in jeopardized myocardium after initial revascularization and at least 1 angiogram during 5-year follow-up were analyzed (n=897). This included 369 CABG-treated patients (16% with diabetes) and 528 PTCA-treated patients (18% with diabetes). The influence of diabetes on angiographic increase in percentage of jeopardized myocardium after initial revascularization with either PTCA or CABG was investigated. Among PTCA patients, the mean percentage increase in total jeopardized myocardium was significantly greater in those with diabetes than in those without at 1-year protocol-directed angiography (42% versus 24%, P=0.05) and on the first clinically performed (unscheduled) angiogram within 30 months (63% versus 50%, P=0.01) but not at 5-year protocol-directed angiography (34% versus 26%, P=0.33). This excess midterm risk associated with diabetes persisted after statistical adjustment. In contrast, among CABG patients, diabetes was not associated with percentage increase in jeopardized myocardium at any angiographic follow-up interval.

CONCLUSIONS

Presence of diabetes differentially influences worsening of jeopardized myocardium after initial PTCA compared with CABG. This differential effect occurs irrespective of whether follow-up angiography is undertaken for clinical or nonclinical purposes.

What constitutes optimal surgical revascularization? Answers from the Bypass Angioplasty Revascularization Investigation (BARI)

OBJECTIVES

The study was done to derive the optimum definition of complete revascularization in coronary artery bypass surgery.

BACKGROUND

"Complete revascularization" has been considered the goal of coronary artery bypass operations, but various definitions of completeness exist.

METHODS

We evaluated the Bypass Angioplasty Revascularization Investigation (BARI) surgical results in the seven years after operation. Different definitions of completeness of revascularization were retrospectively applied to the 1,507 patients in the combined randomized/registry group to derive the definition of complete operative revascularization with the best discrimination in long-term results between those with and without complete revascularization as defined. Four definitions were evaluated: 1) traditional complete revascularization with one graft to each major diseased artery system; 2) functional complete revascularization with one graft to all diseased major or primary segmental vessels; 3) number of distal anastomoses greater than, equal to or less than the number of diseased coronary segments; and 4) number of distal anastomoses to the major coronary systems equal to 1 or greater than 1.

RESULTS

No independent survival advantage existed for traditional or functional complete revascularization as compared with incomplete revascularization. No survival advantage existed for any of the three arms of definition 3. For definition 4, seven-year death/myocardial infarction was highest (32.9%) when more than one anastomosis was constructed to any non-left anterior descending coronary artery (LAD) system (relative risk 1.37, p = 0.03). No increased risk was associated with constructing more than one anastomosis into the LAD system.

CONCLUSIONS

The construction of more than one graft to any system other than the LAD appears to confer no long-term advantage, and may actually be deleterious.

Validation of three myocardial jeopardy scores in a population-based cardiac catheterization cohort

BACKGROUND

The Jeopardy Score from Duke University and the Myocardial Jeopardy Index from the Bypass Angioplasty Revascularization Investigation (BARI) have been validated but never applied to a large unselected cohort. We assessed the prognostic value of these existing jeopardy scores, along with that of a new Lesion Score developed for the Alberta Provincial Project for Outcome Assessment in Coronary Heart Disease (APPROACH), a clinical data collection initiative capturing all patients undergoing cardiac catheterization in the province of Alberta.

METHODS

The predictive value of these three scores were compared in a cohort of >20,000 patients (9922 treated medically, 6334 treated with percutaneous intervention, and 3811 treated with bypass surgery). Scores were considered individually in logistic regression models for their ability to predict outcome and then added to models containing sociodemographic data, comorbidities, ejection fraction, indication for procedure, and descriptors of coronary anatomy.

RESULTS

All scores were found to be predictive of 1-year mortality, especially when patients are treated medically or with percutaneous intervention. In these patients, the APPROACH Lesion Score performed slightly better than the other jeopardy scores. The Duke Jeopardy Score was most predictive in those patients undergoing coronary bypass surgery.

CONCLUSIONS

Myocardial jeopardy scores provide independent prognostic information for patients with ischemic heart disease, especially if those patients are treated medically or with percutaneous intervention. These scores represent potentially valuable tools in cardiovascular outcome studies. The APPROACH Lesion Score may perform slightly better than previously developed jeopardy scores.

Coronary revascularization without cardiopulmonary bypass in high-risk patients: a route to the future

Previous reports have demonstrated that reoperative coronary revascularization, advanced age, female sex, and impaired left ventricular dysfunction are independent predictors of operative mortality after coronary artery bypass grafting (CABG). CABG without cardiopulmonary bypass (off-pump CABG) has been proposed as a potential therapeutic alternative in these high-risk patient groups. Despite the substantial learning curve associated with off-pump CABG, early outcomes of off-pump CABG in high-risk patients are better than those associated with the conventional on-pump CABG approach. These results suggest that off-pump CABG is a safe alternative to on-pump CABG in high-risk patients. Randomized prospective studies are needed to validate the results of these initial retrospective reports and to demonstrate the long-term benefits of this approach.

The effect of previous coronary-artery bypass surgery on the prognosis of patients with diabetes who have acute myocardial infarction. Bypass Angioplasty Revascularization Investigation Investigators

BACKGROUND

Acute myocardial infarction in patients with diabetes is associated with high mortality. We studied whether previous revascularization by coronary-artery bypass grafting (CABG), as compared with percutaneous transluminal coronary angioplasty (PTCA), influences the prognosis in such patients.

METHODS

We classified all patients eligible for the Bypass Angioplasty Revascularization Investigation who underwent coronary revascularization within three months after entry into the study according to whether they had diabetes and whether they had undergone CABG, either initially or after PTCA. The protective effect of CABG with regard to mortality in the presence and in the absence of subsequent spontaneous Q-wave myocardial infarction was estimated with the use of Cox regression models.

RESULTS

Among the 641 patients with diabetes and the 2962 without diabetes, the cumulative five-year rates of death were 20 percent and 8 percent, respectively (P<0.001), and the five-year rates of spontaneous Q-wave myocardial infarction were 8 percent and 4 percent (P<0.001). CABG greatly reduced the risk of death after spontaneous Q-wave myocardial infarction in the patients with diabetes (relative risk, 0.09; 95 percent confidence interval, 0.03 to 0.29). Among patients with diabetes who had undergone CABG but did not have spontaneous Q-wave myocardial infarctions, the corresponding relative risk of death was 0.65 (95 percent confidence interval, 0.45 to 0.94). Among the patients without diabetes, no protective effect of CABG was evident.

CONCLUSIONS

Among patients with diabetes, previous coronary bypass surgery, as compared with coronary angioplasty, has a highly favorable influence on prognosis after acute myocardial infarction and a smaller beneficial effect among patients who do not have infarction. These findings should influence the type of coronary revascularization procedure selected for patients with diabetes who have multivessel coronary artery disease.