Contemporary practice of coronary revascularization in U.S. hospitals and hospitals participating in the bypass angioplasty revascularization investigation (BARI)

Objectives. To assess generalizability of the Bypass Angioplasty Revascularization Investigation (BARI), we conducted a separate study comparing revascularization in U.S. and BARI hospitals.Background. The BARI trial is a multicenter investigation comparing initial revascularization with percutaneous transluminal coronary angioplasty and coronary bypass graft surgery in patients with symptomatic multivessel coronary disease.Methods. All revascularization procedures during 5 consecutive workdays were surveyed at 75 U.S. hospitals offering coronary angioplasty and bypass surgery and at all BARI hospitals. Data collected were demographics, extent of disease and type of current and previous revascularization.Results. At both U.S. and BARI hospitals, 57% of all revascularization procedures were coronary angioplasty and 43% were bypass surgery. The U.S. hospitals had m ore patients with single-vessel disease, acute myocardial infarction and primary procedures. Other characteristics were similar. The majority of revascularization procedures were angioplasty for single-vessel disease (U.S. 32% vs. BARI 25%) and bypass surgery for triple-vessel disease (U.S. 31% vs. BARI 31%). Overall, the choice between bypass surgery and angioplasty was similar in BARI and U.S. hospitals (adjusted odds ratio [OR] 1.0, p = 0.914). However, older patients were more likely and younger patients less likely to undergo bypass surgery in BARI versus U.S. hospitals (older patients: adjusted OR 1.6, p = 0.031; younger patients: adjusted OR 0.6, p = 0.028). The BARI protocol would have excluded 65% of all candidates for revascularization, for whom indications already exist for angioplasty or bypass surgery, and another 23%, for whom angioplasty would be contraindicated for individual lesions.Conclusions. Patients undergoing coronary revascularization in BARI and U.S. hospitals were generally similar, as was the choice between types of revascularization. Results from the BARI trial apply to ∼300 (12%) candidates for coronary revascularization/workday.     

Effect of body mass index on early outcomes in patients undergoing coronary artery bypass surgery

OBJECTIVES: This study sought to quantify the effect of body mass index (BMI) on early clinical outcomes following coronary artery bypass grafting (CABG). BACKGROUND: Obesity is considered a risk factor for postoperative morbidity and mortality after cardiac surgery, although existing evidence is contradictory. METHODS: A concurrent cohort study of consecutive patients undergoing CABG from April 1996 to September 2001 was carried out. Main outcomes were early death; perioperative myocardial infarction; infective, respiratory, renal, and neurological complications; transfusion; duration of ventilation, intensive care unit, and hospital stay. Multivariable analyses compared the risk of outcomes between five different BMI groups after adjusting for case-mix. RESULTS: Out of 4,372 patients, 3.0% were underweight (BMI <20 kg/m(2)), 26.7% had a normal weight (BMI >or=20 and <25 kg/m(2)), 49.7% were overweight (BMI >or=25 and <30 kg/m(2)), 17.1% obese (BMI >or=30 and <35 kg/m(2)) and 3.6% severely obese (BMI >or=35 kg/m(2)). Compared with the normal weight group, the overweight and obese groups included more women, diabetics, and hypertensives, but fewer patients with severe ischemic heart disease and poor ventricular function. Underweight patients were more likely than normal weight patients to die in hospital (odds ratio [OR] = 4.0, 95% CI 1.4 to 11.1), have a renal complication (OR = 1.9, 95% confidence interval [CI] 1.0 to 3.7), or stay in hospital longer (>7 days) (OR = 1.7, 95% CI 1.1 to 2.5). Overweight, obese, and severely obese patients were not at higher risk of adverse outcomes than normal weight patients, and were less likely than normal weight patients to require transfusion (ORs from 0.42 to 0.86). CONCLUSIONS: Underweight patients undergoing CABG have a higher risk of death or complications than normal weight patients. Obesity does not affect the risk of perioperative death and other adverse outcomes compared to normal weight, yet obese patients appear less likely to be selected for surgery than normal weight patients.     

Effects of heart failure and diabetes mellitus on long-term mortality after coronary revascularization (from the BARI Trial)

This study evaluated the effect of heart failure (HF) and ejection fraction (EF) at baseline on long-term cardiac mortality in patients undergoing coronary revascularization and investigated the effect of diabetes mellitus (DM) on mortality. We evaluated long-term outcomes of patients without HF, HF and a preserved EF, and HF and a decreased EF who underwent revascularization with percutaneous transluminal coronary angioplasty or coronary artery bypass graft surgery after enrollment in the Bypass Angioplasty Revascularization Investigation (BARI) trial. Ten years after initial revascularization, cumulative rates of freedom from cardiac death were 90% in patients without HF, 75% in patients with HF and a preserved EF, and 59% in patients with HF and a decreased EF (p <0.001, 3-way comparison). In diabetic patients with HF and a preserved EF, there was a significant increase in cardiac mortality compared with patients without HF (p <0.001); however, this relation was not seen in patients without DM. In conclusion, patients with HF and a preserved EF have increased mortality over 10 years compared with those without HF. Only in patients with DM did HF with preserved EF confer additional risk.     

Methodology of serial ECG classification using an adaptation of the NOVACODE for Q wave myocardial infarction in the bypass angioplasty revascularization investigation (BARI)

Serial electrocardiographic (ECG) changes are a critical component of the diagnostic algorithm for classification of myocardial ischemic events in large-scale clinical trials. This study describes a computerized serial ECG classification program developed at the St. Louis University Core ECG Laboratory for use in the Bypass Angioplasty Revascularization Investigation (BARI) trial, in which patients with multivessel coronary artery disease were randomized to receive either coronary artery bypass grafting or percutaneous transluminal coronary angioplasty. The St. Louis University program detects and codes serial changes in Q, ST, and T wave items according to Minnesota code (MC) criteria using a modified NOVACODE hierarchical classification system. Measurements using a seven-power calibrated coding loupe are used to generate the MC from a customized software program. Significant minor or major changes are detected by the serial comparison program and referred to a physician coder for verification. Serial comparison coding rules are used to adjust for weaknesses in the standard MC classification system resulting from instability at decision boundaries. Of 4,244 BARI randomized and registry study participants with follow-up ECGs received at the Core ECG Laboratory as of March 1995, a grade 2 MC Q wave progression was noted in 568 participants (13.4%) using MC criteria alone, as compared with 367 (8.6%) after the St. Louis University coding rules were applied. The incidence of grade 1 MC Q wave progressions was 16.4% (697/4,244) versus 6.1% (259/4,244) when the St. Louis University program was applied. Intraobserver variability for grade 2 Q wave progression codes determined from a sample of 812 serial ECG comparisons revealed kappa statistics of 0.88, 0.84, and 1.0 for the anterior, inferior, and lateral lead groups, respectively. In conclusion, the use of the standard MC in this multicenter clinical trial of patients with multivessel coronary disease indicates that additional coding rules are necessary to adjust for intrinsic weaknesses and instability at decision boundaries in the code resulting from biologic variability and coding variation.     

A comparison of short- and long-term outcomes for balloon angioplasty and coronary stent placement

OBJECTIVES: We sought to compare patient outcomes for coronary stent placement and balloon angioplasty. BACKGROUND: Since 1994, the number of patients treated only with balloon angioplasty has decreased nationally, whereas the use of coronary stents as an alternative has grown tremendously. The objectives of this study were to compare short- and long-term survival and subsequent revascularization rates for patients undergoing single-vessel balloon angioplasty and coronary stent placement. METHODS: New York's Coronary Angioplasty Registry was used to identify New York patients undergoing either balloon angioplasty or stent placement between July 1, 1994, and December 31, 1996. Statistical models were used to compare risk-adjusted short- and long-term survival and subsequent coronary artery bypass graft surgery (CABG) and percutaneous coronary interventions (PCIs). RESULTS: No significant differences were found in adjusted in-patient mortality, but patients who had balloon angioplasty were, on average, 1.36 times more likely to have died at any time during the two-year period after the index procedure (p = 0.003). The adjusted in-patient CABG rate was significantly higher for balloon angioplasty (2.72% vs. 1.66%, p<0.0001), and the adjusted two-year CABG rate was also significantly higher for balloon angioplasty (10.81% vs. 7.25%, p<0.001). The adjusted two-year rate for subsequent PCIs was also significantly higher for balloon angioplasty (19.6% vs. 14.3%, p<0.0001). Although measures were taken to eliminate or minimize the effect of selection bias, it should be noted that patients with stents were healthier at hospital admission than patients who had balloon angioplasty. CONCLUSIONS: Stent placement is associated with significantly lower risk-adjusted long-term mortality, CABG and subsequent PCI rates, as compared with balloon angioplasty.     

Effect of body mass index on risk of long-term mortality following coronary artery bypass grafting

The effect of obesity on long-term mortality after coronary artery bypass grafting (CABG) remains inconclusive, partly due to methodologic issues in previous studies. We examined the effect of obesity on long-term mortality (up to a 6-year follow-up) in adult patients with a body mass index (BMI) > or =18.5 kg/m2 who underwent CABG at Baylor University Medical Center (Dallas, Texas) between January 1998 and August 1999 (n = 1,209). Unadjusted analysis indicated a strong association between BMI and long-term mortality (p = 0.001), with a decreased risk of mortality associated with increasing BMI. After adjusting for factors shown to be confounders of this relation (age, diabetes mellitus, chronic obstructive lung disease, renal failure, ejection fraction, and left main disease), the estimated association was no longer significant (p = 0.425). In conclusion, the apparent survival benefit associated with higher BMI became nonsignificant when the relation between mortality and BMI was adjusted, first for age and then for diabetes mellitus, chronic obstructive lung disease, renal failure, ejection fraction, and left main disease. This relation was masked in the crude analysis primarily by the effect of age. Patients with a high BMI were typically younger than patients with a lower BMI, suggesting that physicians and surgeons may only recommend/perform CABG for patients with a high BMI with an otherwise lower risk profile.     

Prevalence and impact of renal insufficiency on clinical outcomes of patients undergoing coronary revascularization.

BACKGROUND: Patients with renal insufficiency are more likely to die after coronary revascularization, but mild renal insufficiency is neglected and little is known about its clinical effects. METHODS AND RESULTS: In the present study 3,025 patients grouped by estimated creatinine clearance (CrCl) were analyzed to evaluate the association between CrCl and clinical outcome. The mean serum creatinine was 1.0+/-0.4 mg/dl, with 4.3% above normal; in 65.8% CrCl was <90 ml/min. During hospitalization, there were significant differences in mortality among the groups stratified by CrCl (p<0.0001). During follow-up after hospital discharge, there were significant differences in mortality (p<0.0001), new-onset myocardial infarction (p=0.007), and stroke (p=0.032). In patients with severe renal insufficiency, the in-hospital and follow-up mortality reached 15.4% and 31.3%, respectively. The independent risk factors for all-cause death after revascularization were the mode of revascularization, age and the CrCl level. In patients with mild renal insufficiency or normal renal function, the all-cause mortality after percutaneous coronary intervention was significantly lower than that after CABG. CONCLUSIONS: Renal insufficiency is not rare in patients undergoing coronary revascularization and in the present study even mild renal insufficiency correlated with adverse clinical outcomes after revascularization. In patients with normal renal function or mild renal insufficiency, the mode of revascularization might lead to a prognostic difference.     

Outcomes of noncardiac surgery after coronary bypass surgery or coronary angioplasty in the Bypass Angioplasty Revascularization Investigation (BARI)

PURPOSE: Previous studies have shown that coronary artery bypass surgery reduces the risk of cardiac complications after noncardiac surgery. Whether coronary angioplasty provides equivalent protection is not known. SUBJECTS AND METHODS: Patients were randomly assigned to undergo cardiac artery bypass surgery or angioplasty as part of the Bypass Angioplasty Revascularization Investigation trial. All subsequent noncardiac surgeries during a mean (+/- SD) follow-up of 7.7 years were recorded among participants in the ancillary Study of Economics and Quality of Life. Rates of mortality and nonfatal myocardial infarction, length of stay, and hospital costs were compared by the original randomized assignment. RESULTS: A total of 501 patients had noncardiac surgery at a median of 29 months after their most recent coronary revascularization procedure. Mortality and nonfatal myocardial infarction within 30 days of the first noncardiac surgery occurred in 4 of the 250 of the surgery-assigned patients and in 4 of the 251 of the angioplasty-assigned patients (P = 1.0). There were no significant differences in the mean length of hospital stay (6.3 +/- 6.7 versus 6.2 +/- 6.8 days; P = 0.47) or hospital cost ($8,920 +/- $11,511 versus $7,785 +/- $7,643; P = 0.33) between the surgery and angioplasty groups. Similar results were obtained when subsequent noncardiac procedures were included in the analysis. CONCLUSION: Rates of myocardial infarction and death after noncardiac surgery are similarly low after contemporary bypass surgery or angioplasty in patients with multivessel coronary artery disease.     

The optimal mode of coronary revascularization for diabetics: A risk-adjusted long-term study comparing coronary angioplasty and coronary bypass surgery

Aims Some recent studies have reported superior outcomes for diabeticpatients following coronary bypass surgery compared with coronaryangioplasty. However, the available data are conflicting, arebased on relatively small numbers of diabetic patients, andhave limited duration of follow-up. The aims of this study wereto compare risk adjusted long- term survival in diabetic patientsfollowing first-time revascularization via either coronary bypasssurgery or coronary angioplasty; and, to identify variablesindependently associated with mortality. Methods and Results This was a two centre database project involving 15809 patientsundergoing either coronary angioplasty or coronary bypass surgeryas their initial revascularization procedure. Diabetes was presentin 1938 (12%). Mean follow-up was 4·6±2·7years for angioplasty and 6·6±4·3 yearssurgery diabetic patients. Multivariable time-related analysesin the hazard function domain for death were performed. Overallten-year survival for pharmacologically treated diabetics wasbetter after coronary bypass surgery (60%) than angioplasty(46%, <0·0001). However, the risk-adjusted survivaladvantage conferred by bypass surgery over angioplasty was strongestfor patients receiving oral agents for diabetic control (75%vs 62%) and less impressive for diet (84% vs 81%) and insulin-treateddiabetics (63% vs 64%). The major factors independently associatedwith worse outcome after angioplasty were incomplete revascularization,and the use of a sulfonylurea agent. The use of the left internalmammary graft improved survival in surgical patients. Conclusions In general, diabetic patients had better long-term survivalafter bypass surgery than angioplasty. Incomplete revascularizationand sulfonylurea therapy worsened outcome after angioplasty,and use of the left internal mammary improved outcome afterbypass surgery.The European Society of Cardiology     

Influence of diabetes mellitus on long-term (five-year) outcomes of drug-eluting stents and coronary artery bypass grafting for multivessel coronary revascularization

Diabetes mellitus is a major risk factor for coronary artery disease (CAD) and for diffuse and progressive atherosclerosis. We evaluated the outcomes of drug-eluting stent (DES) placement and coronary artery bypass grafting (CABG) in 891 diabetic patients (489 for DES implantation and 402 for CABG) and 2,151 nondiabetic patients (1,058 for DES implantation and 1,093 for CABG) with multivessel CAD treated from January 2003 through December 2005 and followed up for a median 5.6 years. Outcomes of interest included death; the composite outcome of death, myocardial infarction (MI), or stroke; and repeat revascularization. In diabetic patients, after adjusting for baseline covariates, 5-year risk of death (hazard ratio 1.01, 95% confidence interval 0.77 to 1.33, p = 0.96) and the composite of death, MI, or stroke (hazard ratio 1.03, 95% confidence interval 0.80 to 1.31, p = 0.91) were similar in patients undergoing DES or CABG. However, rate of repeat revascularization was significantly higher in the DES group (hazard ratio 3.69, 95% confidence interval 2.64 to 5.17, p <0.001). These trends were consistent in nondiabetic patients (hazard ratio 0.80, 95% confidence interval 0.55 to 1.16, p = 0.23 for death; hazard ratio 0.77, 95% confidence interval 0.56 to 1.05, p = 0.10 for composite of death, MI, or stroke; hazard ratio 2.77, 95% CI 1.95 to 3.91, p <0.001 for repeat revascularization). There was no significant interaction between diabetic status and treatment strategy on clinical outcomes (p for interaction = 0.36 for death; 0.20 for the composite of death, MI, or stroke; and 0.40 for repeat revascularization). In conclusion, there was no significant prognostic influence of diabetes on long-term treatment with DES or CABG in patients with multivessel CAD.     

Comparison of long-term (seven year) outcomes among patients undergoing percutaneous coronary revascularization with versus without stenting

Coronary stents have markedly improved the short- and intermediate-term safety and efficacy of percutaneous coronary intervention by improving acute gains in luminal dimensions, decreasing abrupt vessel occlusion, and decreasing restenosis, yet the long-term benefit of coronary stenting remains uncertain. We examined long-term clinical outcomes of death, myocardial infarction, and repeat target vessel revascularization (TVR) among patients enrolled in the Duke Database for Cardiovascular Disease who underwent revascularization with percutaneous transluminal coronary angioplasty alone or stent placement from 1990 to 2002. Among 6,956 patients who underwent percutaneous revascularization, propensity modeling was applied to identify 1,288 matched patients with a similar likelihood to receive coronary stents according to clinical, angiographic, and demographic characteristics. Significant (p <0.05) predictors of stent placement included multivessel disease, diabetes, hypertension, recent myocardial infarction, decreased ejection fraction, and year of study entry. At a median follow-up of 7 years, although treatment with coronary stenting was associated with a significant and sustained decrease in repeat TVR (18.0% vs 28.1%, p = 0.0002) and the occurrence of death, myocardial infarction or TVR (39.2% vs 45.8%, p = 0.004), long-term survival did not significantly differ between treatment groups (19.9% vs 20.5%, p = 0.72). Outcomes of death and myocardial infarction did not significantly differ between patients who did and did not undergo repeat TVR. In conclusion, compared with angioplasty alone, revascularization with coronary stents provides a significant early and sustained decrease in the need for repeat revascularization, but stents do not influence long-term survival.     

Clinical and angiographic correlates of short- and long-term mortality in patients undergoing coronary artery bypass grafting

Differences in the clinical and angiographic factors associated with short- and long-term outcomes in patients undergoing coronary artery bypass grafting (CABG) are less known. Accordingly, differences were examined in clinical and angiographic correlates of short- and long-term mortality after CABG in 8,229 patients undergoing initial CABG enrolled in the Duke Cardiovascular Disease Database (1995 to 2002). Logistic regression and Cox proportional hazard modeling were performed to determine independent correlates of 30-day and long-term mortality. Death occurred in 2.4% at 30 days and 17.6% beyond 30 days at a median follow-up of 6 years in patients who underwent CABG. Multivariable models identified older age, lower left ventricular ejection fraction, lower or higher body mass index, cerebrovascular disease, lack of internal mammary artery use, and lower cholesterol to be associated with increased risk of both events. Although hemodynamic status (preoperative myocardial infarction, New York Heart Association class, and cardiogenic shock), female gender, and minority race were associated with 30-day death; co-morbid conditions (serum creatinine, chronic lung disease, diabetes, previous heart failure, peripheral vascular disease, and left main disease) were associated with increased long-term (beyond 30 days) death (c indexes 0.76 and 0.79 for the short- and long-term mortality models, respectively). In conclusion, our study suggested that correlates of acute and long-term death were different in patients undergoing CABG. These differences should be kept in context when counseling patients undergoing CABG and may help facilitate targeted strategies to improve short- and long-term mortality risks after CABG.     

Association between body mass index and outcome of coronary artery bypass

Studies have shown disparate findings regarding body mass index and outcomes after coronary artery bypass. We analyzed body mass index and other clinical variables that might predict morbidity and mortality after primary isolated coronary artery bypass. Data on 4,425 patients (79% men) were reviewed retrospectively. They were classified as underweight (1.6%), normal weight (65%), obese (32%), and morbidly obese (1.4%) according to body mass index <20, 20-29, 30-39, and >40 kg·m(-2), respectively. Multiple logistic regression was used for correlates of 30-day outcome. Cox regression was used for predictors of late outcome in underweight and morbidly obese patients. There were 45 (1%) deaths and 234 (5%) cases of morbidity within 30 days. Independent correlates of 30-day morbidity were smoking, logistic EuroSCORE, blood and blood product transfusions. Correlates of 30-day mortality were logistic EuroSCORE and blood transfusion. The only independent predictor of late death in underweight and morbidly obese patients was preoperative arrhythmia. Body mass index was not a predictor of 30-day morbidity or mortality. The 1-, 3-, and 7-year survival rates were not significantly different between underweight and morbidly obese patients. Body mass index did not affect short-term outcomes after primary coronary artery bypass grafting.