Seven-year outcome in the Bypass Angioplasty Revascularization Investigation (BARI) by treatment and diabetic status

Abstract

Objectives: To compare seven-year survival in the Bypass Angioplasty Revascularization Investigation (BARI) patients randomly assigned to percutaneous transluminal coronary angioplasty (PTCA) versus coronary artery bypass grafting (CABG).

Background: The primary results of BARI reported no significant difference in five-year survival between CABG and PTCA groups. However, among patients with treated diabetes mellitus, a subgroup not specified a priori, a striking difference was seen in favor of CABG.

Methods: Symptomatic patients with multivessel disease (n = 1,829) were randomly assigned to initial treatment strategy of CABG or PTCA and followed for an average of 7.8 years. The intention-to-treat principle was used to extend the initial five-year BARI treatment comparisons.

Results: Kaplan-Meier estimates of seven-year survival for the total population were 84.4% for CABG and 80.9% for PTCA (p = 0.043). This difference could be explained by the 353 patients with treated diabetes mellitus for whom estimates of seven year survival were 76.4% CABG and 55.7% PTCA (p = 0.0011). Among the remaining 1,476 patients without treated diabetes, survival was virtually identical by assigned treatment (86.4% CABG, 86.8% PTCA, p = 0.72). The PTCA group had substantially higher subsequent revascularization rates than the CABG group (59.7% vs. 13.1%, p < 0.001); however, the changes between the five- and seven-year rates were similar for the two groups.

Conclusions: At seven years, there was a statistically significant survival advantage for patients randomized to CABG compared with PTCA. Among patients with treated diabetes mellitus, the benefit of CABG over PTCA seen at five years was more pronounced at seven years; among nondiabetic patients, there was essentially no treatment difference.