Off or on bypass: what is the safety threshold?

Background: To identify the technical profile of the patients operated on without cardiopulmonary bypass (CPB) and the benefit of the procedure.

Methods: From May 21, 1997, to December 31, 1998, 785 patients had coronary artery bypass grafting through a median sternotomy (group A: 472 without CPB; group B: 290 with CPB; group C: 23 converted). Technical aspects, mortality rate, cerebrovascular accident (CVA) incidence (crude and risk-adjusted), and incidence of major complications were recorded.

Results: Patients without CPB had mainly one to three grafts and one- or two-vessel disease. Multiple arterial grafting was not a limit, whereas sequential grafting was. Group A had lower complications rates, shorter intensive care unit and postoperative in hospital stays, and lower transfusion rates. Mortality rates and CVA incidence (crude and risk-adjusted) were similar in both groups and in each subgroup considered. In group A, a lower complications rate was present in some patients (aged greater than 70 years, female, with unstable angina). Group C showed higher mortality and complications rates. Failure of revascularization showed no difference between groups.

Conclusions: Primary endpoints are not affected by the surgical strategy, whereas some of the secondary endpoints are. However, patients in group A experienced fewer complications. Both techniques can give satisfying results and must be applied according to the surgeon's preference.