Off-pump coronary artery bypass surgery lacks a longitudinal survival advantage in patients with left ventricular dysfunction.

Abstract

This study evaluates the longitudinal impacts of off-pump coronary artery bypass (OPCAB) surgery in patients with reduced left ventricular ejection fraction (LVEF). Adults with LVEF ≤ 30% undergoing coronary artery bypass grafting between 2011 and 2020 were included. Patients were stratified based on the utilization of cardiopulmonary bypass into OPCAB or on-pump coronary artery bypass (ONCAB) groups. Primary outcomes included survival and hospital readmissions. Secondary outcomes evaluated postoperative morbidities. Multivariable regression evaluated risk-adjusted mortality and readmission. Propensity score matching was utilized to reduce bias. A total of 660 low LVEF patients were included, of which 28.5% (n = 188) were OPCAB and 71.5% (n = 472) were ONCAB. The rates of complete revascularization were similar between the groups (80.3% vs 82.0%; P = .67). Early survival between the unmatched groups was similar at 1-year follow-up (86.2% vs 87.9%; P = .53); however, at 5 years OPCABs had significantly worse survival compared with ONCABs (71.5% vs 64.2%; P = .02). These findings persisted in the matched cohort where survival at 1 year was comparable (86.8% vs 85.7%; P = .80), but 5-year survival was better for ONCABs (64.1% vs 69.9%; P = .03). The rates of readmission were similar between the unmatched and matched groups at all time intervals, including readmissions for cardiac-related and heart failure-related events (all, P > .05). In contemporary patients with reduced LVEF, survival after OPCAB was similar at 1 year but lower at 5-year follow-up compared with ONCAB, despite similar rates of complete revascularization. These findings suggest that there may be other factors influencing longitudinal mortality in the low LVEF cohort, beyond the use of cardiopulmonary bypass.