Comparable survival over an extended follow-up after on-pump versus off-pump coronary artery bypass grafting: a propensity score-matched cohort

Long-term survival following off-pump coronary artery bypass grafting (OPCAB) compared with conventional on-pump coronary artery bypass grafting (ONCAB) remains uncertain. Randomised trials and meta-analyses up to 5–10 years after procedures have demonstrated either no significant differences or modest disadvantages of OPCAB, particularly regarding completeness of revascularisation and late mortality. However, comparative data extending up to 20 years after procedure are scarce. Thus, very-long-term outcomes after ONCAB versus OPCAB in a propensity score-matched cohort were evaluated.

Consecutive adults undergoing isolated primary coronary artery bypass grafting between 1999 and 2016 at a single cardiac surgery centre were retrospectively identified. Patients undergoing isolated OPCAB or ONCAB procedures were included and matched in a 1:2 ratio using clinically relevant preoperative variables. The primary outcome was overall survival in the matched cohort analysed using Cox proportional hazards regression.

During the study period, 2,935 patients underwent isolated primary coronary artery bypass grafting (CABG), of whom 2,496 (85.0%) underwent ONCAB and 439 (15.0%) OPCAB procedures. Median survival time was 13.7 years (95% CI 13.2–14.2) and median follow-up was 12.3 years (interquartile range 8.0–17.1, maximum 23.9 years). The matched cohort consisted of 402 OPCAB patients matched to 804 ONCAB patients. Median survival time was 12.4 years (95% CI 11.9–13.2) in ONCAB and 12.6 years (95% CI 11.5–13.8) in OPCAB patients. Overall survival did not differ significantly between the groups (HR 0.95, 95% CI 0.82–1.11; ONCAB as reference). No significant differences were observed in the cumulative incidence of cardiovascular mortality.

In this propensity score-matched cohort with follow-up extending up to 20 years, ONCAB and OPCAB were associated with comparable long-term survival and cardiovascular mortality. These findings support an individualised approach to operative technique selection based on patient characteristics and surgical expertise.