Off-pump coronary surgery: effect on early mortality and stroke.

Background: Avoiding cardiopulmonary bypass in coronary artery bypass grafting is thought to reduce early mortality and morbidity.

Methods: We used our prospective database to compare all patients having off-pump coronary surgery (n = 389) with those having on-pump coronary surgery (n = 2412) between March 15, 1995, and November 1, 2000. Patients were grouped by age (years) in decades (>90, 80-89, 70-79, 60-69, <60 years). The Northern New England risk model was applied. Thirty-two independent variables were entered into a stepwise logistic regression analysis with the end points being surgical mortality and postoperative stroke.

Results: Patients undergoing off-pump operations were older (70.9 +/- 12 vs 68.1 +/- 11 years; P <.001), and their Northern New England predicted risk was higher (11.9% +/- 13% vs 9.2% +/- 10%; P <.001). However, patients having on-pump bypass had significantly more bypass grafts constructed (3.3 +/- 0.8 vs 1.9 +/- 0.8; P <.001) and triple-vessel coronary artery disease (58% vs 28%; P <.001). There were no significant differences in postoperative mortality, stroke rate, complications, and length of stay between the groups. Logistic regression analysis did not show that cardiopulmonary bypass was a risk factor for either surgical mortality (odds ratio, 1.08; P =.83) or stroke (odds ratio, 1.59; P =.27).

Conclusions: Off-pump coronary bypass did not reduce early mortality and morbidity. Early and late results should be compared in a prospective randomized study.