Ten-year outcomes after off-pump and on-pump coronary artery bypass grafting: an inverse probability of treatment weighting comparative study.

Aims: The debate on the advantages and limitations of off-pump myocardial revascularization (OPCAB) on long-term outcomes has not still arrived to a conclusion. This study was designed to compare the impact of OPCAB vs, on-pump coronary artery bypass grafting (CABG) on long-term mortality and major adverse cardiac and cerebrovascular events (MACCEs).

Methods: The PRIORITY project was designed to evaluate the long-term outcomes of two large prospective multicenter cohort studies on CABG. Data on isolated CABG were linked to two administrative datasets. The inverse probability of treatment weight was employed to balance the treatment groups. Time-to-event methods were employed to analyze endpoints.

Results: The cohort consisted of 10 988 patients who underwent isolated CABG (27.2% OPCAB). The median follow-up time was 7.9 years and was 100% complete. Unadjusted long-term survival was significantly worst for OPCAB, confirmed by weighted models (hazard ratio 1.08, 95% confidence interval (CI) 1.01-1.14, P = 0.01). OPCAB was associated to an increased risk of MACCE at 10 years (weighted hazard ratio 1.18, 95% CI 1.12-1.23, P < 0.001). Inside the MACCEs, OPCAB was significantly related to increased incidence of repeat revascularization (hazard ratio 2.27, 95% CI 1.39-3.85, P < 0.001, in the first 6 months, hazard ratio 1.19, 95% CI 1.09-1.32, P < 0.001 afterward) and stroke (hazard ratio 1.22, 95% CI 1.10-1.35, P < 0.001).

Conclusion: The results of this study suggest that OPCAB was associated with an increased risk of mortality, repeat myocardial revascularization and stroke at 10 years compared with on-pump CABG.