An overlap‐weighted analysis on 10‐year survival of off‐pump versus on‐pump coronary artery grafting in multivessel coronary artery disease

Background and Objective The introduction of off-pump coronary artery bypass surgery intended to overcome some of the conventional on-pump procedure limitations by avoiding potentially harmful adverse effects of extracorporeal circulation and aortic cross-clamping. However, the doubt remains on whether it is associated with worse long-term outcomes. To compare long-term survival in patients with multivessel ischemic heart disease undergoing off-pump versus on-pump coronary artery bypass grafting. Methods Retrospective analysis of 4788 consecutive patients undergoing primary isolated multivessel coronary artery bypass grafting surgery, performed from 2000 to 2015, in Northern Portugal. Among the study population, we identified 1616 and 3172 patients that underwent off-pump and on-pump coronary artery grafting, respectively. We employed a propensity-score-based overlap weighting (OW) algorithm to restrict confounding by indication. The primary endpoint was all-cause mortality at 10 years. Results The mean age of the study population was 63.9 (+/- 9.8) years, and 951 (19.9%) were females. OW was effective in eliminating differences in all major baseline characteristics. Follow-up was 100% complete. The median follow-up time was 12.80 (9.62, 16.62) years. The primary endpoint of all-cause mortality at 10 years occurred in 431 patients (26.7%) in the off-pump group, as compared with 863 (27.2%) in the on-pump group (hazard ratio, 0.93; 95% confidence interval, 0.83-1.04; p = .196). Conclusions In this longitudinal, population-level comparison of off-pump versus on-pump coronary artery bypass surgery for treating multivessel coronary artery disease, the primary outcome of long-term mortality was identical among both patients' groups.