Complete Coronary Revascularization and Outcomes in Patients Undergoing CABG: Insights from the REGROUP Trial

There is growing evidence in support of complete coronary revascularization (CR). Nonetheless there is no universally accepted definition of CR in patients undergoing CABG. We sought to investigate the outcomes of CR defined as surgical revascularization of any territory supplied by a suitable coronary artery with at least 50% stenosis. We performed a pre-planned subanalysis of the REGROUP clinical trial cohort. Of 1,147 patients who underwent CABG, 810 (70.6%) received CR. The primary outcome was a composite of major adverse cardiac events (MACE), including death from any cause, nonfatal myocardial infarction (MI), or repeat revascularization over a median 4.7 years of follow-up. MACE occurred in 175 patients (21.6%) in the CR group and 86 patients (25.5%) in the incomplete revascularization (IR) group (hazard ratio (HR) =0.87; 95% confidence interval [CI] 0.67 to 1.13; p=0.29). A total of 97 patients (12.0%) in the CR group and 48 patients (14.2%) in the IR group died (HR=0.93; 95% CI, 0.65 to 1.32; p=0.67); nonfatal MI occurred in 49 patients (6.0%) in the CR group and 30 patients (8.9%) in the IR group (HR=0.76; 95% CI, 0.48 to 1.2; p=0.24), and repeat revascularization occurred in 62 patients (7.7%) in the CR group and 39 patients (11.6%) in the IR group (HR=0.64; 95% CI, 0.42 to 0.95; p=0.027). In conclusion among patients with a high burden of comorbidities undergoing CABG in the REGROUP trial over a median follow-up period of a median 4.7 years, CR was associated with similar MACE rates but a reduced risk of repeat revascularization. Longer-term follow-up is warranted.