Ten-year outcomes after off-pump versus on-pump coronary artery bypass grafting: Insights from the Arterial Revascularization Trial

Objective: We performed a post hoc analysis of the Arterial Revascularization Trial to compare 10-year outcomes after off-pump versus on-pump surgery.

Methods: Among 3102 patients enrolled, 1252 (40% of total) and 1699 patients received off-pump and on-pump surgery (151 patients were excluded because of other reasons); 2792 patients (95%) completed 10-year follow-up. Propensity matching and mixed-effect Cox model were used to compare long-term outcomes. Interaction term analysis was used to determine whether bilateral internal thoracic artery grafting was a significant effect modifier.

Results: One thousand seventy-eight matched pairs were selected for comparison. A total of 27 patients (2.5%) in the off-pump group required conversion to on-pump surgery. The off-pump and on-pump groups received a similar number of grafts (3.2 ± 0.89 vs 3.1 ± 0.8; P = .88). At 10 years, when compared with on-pump, there was no significant difference in death (adjusted hazard ratio for off-pump, 1.1; 95% confidence interval, 0.84-1.4; P = .54) or the composite of death, myocardial infarction, stroke, and repeat revascularization (adjusted hazard ratio, 0.92; 95% confidence interval, 0.72-1.2; P = .47). However, off-pump surgery performed by low volume off-pump surgeons was associated with a significantly lower number of grafts, increased conversion rates, and increased cardiovascular death (hazard ratio, 2.39; 95% confidence interval, 1.28-4.47; P = .006) when compared with on-pump surgery performed by on-pump-only surgeons.

Conclusions: The findings showed that in the Arterial Revascularization Trial, off-pump and on-pump techniques achieved comparable long-term outcomes. However, when off-pump surgery was performed by low-volume surgeons, it was associated with a lower number of grafts, increased conversion, and a higher risk of cardiovascular death.