Radial artery grafts vs saphenous vein grafts in coronary artery bypass surgery: a randomized trial.

CONTEXT: Arterial grafts are thought to be better conduits than saphenous vein grafts for coronary artery bypass grafting (CABG) based on experience with using the left internal mammary artery to bypass the left anterior descending coronary artery. The efficacy of the radial artery graft is less clear. OBJECTIVE: To compare 1-year angiographic patency of radial artery grafts vs saphenous vein grafts in patients undergoing elective CABG. DESIGN, SETTING, AND PARTICIPANTS: Multicenter, randomized controlled trial conducted from February 2003 to February 2009 at 11 Veterans Affairs medical centers among 757 participants (99% men) undergoing first-time elective CABG. INTERVENTIONS: The left internal mammary artery was used to preferentially graft the left anterior descending coronary artery whenever possible; the best remaining recipient vessel was randomized to radial artery vs saphenous vein graft. MAIN OUTCOME MEASURES: The primary end point was angiographic graft patency at 1 year after CABG. Secondary end points included angiographic graft patency at 1 week after CABG, myocardial infarction, stroke, repeat revascularization, and death. RESULTS: Analysis included 733 patients (366 in the radial artery group, 367 in the saphenous vein group). There was no significant difference in study graft patency at 1 year after CABG (radial artery, 238/266; 89%; 95% confidence interval [CI], 86%-93%; saphenous vein, 239/269; 89%; 95% CI, 85%-93%; adjusted OR, 0.99; 95% CI, 0.56-1.74; P = .98). There were no significant differences in the secondary end points. CONCLUSION: Among Veterans Affairs patients undergoing first-time elective CABG, the use of a radial artery graft compared with saphenous vein graft did not result in greater 1-year patency. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00054847.

Clinical inference: critically weighing the evidence from trials and registries to make clinical decisions.

The results of even excellent randomized trials are applicable primarily to patients who would have met all of the inclusion criteria and none of the exclusion criteria, specified in the study protocol (generalizability or external validity). In addition, three important sources of potential systematic error, or bias, are as follows: selection bias, confounding, and information bias. Selection bias is relevant to nearly all randomized clinical trials in terms of external validity, or generalizability, of even internally valid results. Selection bias, confounding, and information bias can all limit the internal validity of prospective, registry data. Carefully reading the methods sections of both randomized trial and registry reports, with these potential limitations in mind, is the first step in critically using clinical research to help make more informed clinical decisions.

Cost-effectiveness of coronary artery bypass grafts versus percutaneous coronary intervention for revascularization of high-risk patients.

BACKGROUND: A Department of Veterans Affairs Cooperative Study randomized high-risk patients with medically refractory myocardial ischemia, a group largely excluded from previous trials, to urgent revascularization with either percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG). The present study examined the cost-effectiveness of PCI versus CABG for these high-risk patients. METHODS AND RESULTS: Of 454 patients at 16 Department of Veterans Affairs medical centers, 445 were available for the economic analysis (218 PCI and 227 CABG patients). Total costs were assessed at 3 and 5 years from the third-party payer's perspective, and effectiveness was measured by survival. After 3 years, average total costs were 63,896 dollars for PCI versus 84,364 dollars for CABG patients, a difference of 20,468 dollars (95% confidence interval [CI] 13,918 dollars to 27,569 dollars). CIs were estimated by bootstrapping. Survival at 3 years was 0.82 for PCI versus 0.79 for CABG patients (P=0.34). Precision of the cost-effectiveness estimates were assessed by bootstrapping. PCI was less costly and more effective at 3 years in 92.6% of the bootstrap replications. After 5 years, average total costs were 81,790 dollars for PCI versus 100,522 dollars for CABG patients, a difference of 18,732 dollars (95% CI 9873 dollars to 27,831 dollars), whereas survival at 5 years was 0.75 for PCI patients versus 0.70 for CABG patients (P=0.21). At 5 years, PCI remained less costly and more effective in 89.4% of the bootstrap replications. CONCLUSIONS: PCI was less costly and at least as effective for the urgent revascularization of medically refractory, high-risk patients over 5 years.

Percutaneous coronary intervention versus repeat bypass surgery for patients with medically refractory myocardial ischemia: AWESOME randomized trial and registry experience with post-CABG patients.

OBJECTIVES: This report compares long-term percutaneous coronary intervention (PCI) and coronary artery bypass graft (CABG) survival among post-CABG patients included in the Angina With Extremely Serious Operative Mortality Evaluation (AWESOME) randomized trial and prospective registry. BACKGROUND: Repeat CABG surgery is associated with a higher risk of mortality than first-time CABG. The AWESOME is the first randomized trial comparing CABG with PCI to include post-CABG patients. METHODS: Over a five-year period (1995 to 2000), patients at 16 hospitals were screened to identify a cohort of 2,431 individuals who had medically refractory myocardial ischemia and at least one of five high-risk factors. There were 454 patients in the randomized trial, of whom 142 had prior CABG. In the physician-directed registry of 1,650 patients, 719 had prior CABG. Of the 327 patient-choice registry patients, 119 had at least one prior CABG. The CABG and PCI survivals for the three groups were compared using Kaplan-Meier curves and log-rank tests. RESULTS: The CABG and PCI three-year survival rates were 73% and 76% respectively for the 142 randomized patients (75 and 67 patients) (log-rank = NS). In the physician-directed registry, 155 patients were assigned to reoperation and 357 to PCI (207 received medical therapy); 36-month survivals were 71% and 77% respectively (log-rank = NS). In the patient-choice registry, 32 patients chose reoperation and 74 chose PCI (13 received medical therapy); 36-month survivals were 65% and 86% respectively (log-rank test p = 0.01). CONCLUSIONS: Percutaneous coronary intervention is preferable to CABG for many post-CABG patients.

Health-related quality of life after percutaneous coronary intervention versus coronary bypass surgery in high-risk patients with medically refractory ischemia.

OBJECTIVES: We compared six-month health-related quality of life (HRQL) for high-risk patients with medically refractory ischemia randomized to percutaneous coronary intervention (PCI) versus coronary artery bypass graft (CABG) surgery. BACKGROUND: Mortality rates after PCI and CABG surgery are similar. Therefore, differences in HRQL outcomes may help in the selection of a revascularization procedure. METHODS: Patients were enrolled in a Veterans Affairs multicenter randomized trial comparing PCI versus CABG for patients with medically refractory ischemia and one or more risk factors for adverse outcome; 389 of 423 patients (92%) alive six months after randomization completed an Short Form-36 (SF-36) health status survey. Primary outcomes were the Physical Component Summary (PCS) and Mental Component Summary (MCS) scores from the SF-36. Multivariable analyses were used to evaluate whether PCI or CABG surgery was associated with better PCS or MCS scores after adjusting for over 20 baseline variables. RESULTS: There were no significant differences in either PCS scores (38.7 vs. 37.3 for PCI and CABG, respectively; p = 0.23) or MCS scores (45.5 vs. 46.1, p = 0.58) between the treatment arms. In multivariable models, there remained no difference in HRQL for post-PCI versus post-CABG patients (for PCS, absolute difference = 0.56 +/- standard error of 1.14, p = 0.63; for MCS, absolute difference = -1.23 +/- 1.12, p = 0.27). We had 97% power to detect a four-point difference in scores, where four to seven points is a clinically important difference. CONCLUSIONS: High-risk patients with medically refractory ischemia randomized to PCI versus CABG surgery have equivalent six-month HRQL. Therefore, HRQL concerns should not drive decision-making regarding selection of a revascularization procedure for these patients.