Equivalent midterm outcomes after off-pump and on-pump coronary surgery

Objective: Multiple reports demonstrate that off-pump surgery reduces the early morbidity associated with coronary artery bypass grafting. To determine if there are any differences in later outcomes, we compared midterm results of propensity-matched patients who underwent off- and on-pump coronary artery bypass grafting. Methods: From January 1997 to July 2000, 481 patients underwent off-pump coronary artery bypass grafting and 3231 underwent on-pump coronary artery bypass grafting. Propensity matching was used to match 406 patients from each group. Previously, the propensity-matched off-pump patients were found to have had significantly fewer bypass grafts. These 812 patients were followed for time-related events, including death, myocardial infarction, percutaneous coronary intervention, coronary reoperation, and the combined end point of all-cause mortality, myocardial infarction, and all coronary reintervention. Follow-up was 95% complete. Results: At 4 years, survival was 87.5% after off-pump and 91.2% after on-pump coronary artery bypass grafting (P = .2); freedom from myocardial infarction was 92.6% and 95.7% (P = .7), respectively; freedom from percutaneous coronary intervention was 94.3% and 95.5% (P = .9), respectively; freedom from coronary reoperation was 98.1% and 99.0% (P = .4), respectively; and freedom from the combined end point of all-cause mortality, myocardial infarction, and coronary reintervention was 75.2% and 82.9% (P = .14), respectively. Conclusions: Off-pump and on-pump coronary artery bypass grafting results in equivalent midterm outcomes. Fewer bypass grafts in the off-pump patients did not decrease survival or increase ischemic events at 4 years.