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 fewer 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 end-points 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. (C) 1999 by The Society of Thoracic Surgeons.