Reoperative myocardial revascularization: an analysis of 458 reoperations and 2645 single operations.

A consecutive series of 2645 patients underwent primary coronary bypass grafting while 458 patients underwent reoperative bypass during a 9-year period. The mean age (61 years), sex distribution (83% men) and preoperative risk factors were identical in the two groups. Significantly more patients belonged to New York Heart Association (NYHA) class 4 and were clinically unstable in the reoperative group (P < 0.001). The internal mammary artery was used in 43% of the single operation group but in only 23% of patients who subsequently required reoperation (P < 0.001). In reoperations 61% of the patients had an internal mammary artery graft (P < 0.001). The overall operative mortality rate for single operation was 2.3% (62/2645) versus 9.2% (42/458) for reoperations. Patients with a reoperative interval of more than 1 year had a 8.4% mortality rate, compared with 28% in those reoperated on 1 year or less after the initial operation (P < 0.01). Preoperative myocardial infarction, intra-aortic balloon pump insertion, prolonged ventilatory support and ventricular arrhythmias were all prevalent after reoperations (all P > 0.001), while postoperative myocardial infarctions and re-sternotomy for bleeding did not differ between the groups. Emergency operation, preoperative NYHA class 3-4 and poor left ventricular function were predictors of perioperative mortality in both groups. Left main stem stenosis was an added factor in the reoperative group. After reoperation 93% of the hospital survivors were alive at 5 years after surgery; the cardiac event-free rate was 59% and > 90% of the patients showed improvement of their NYHA class during the follow-up. Reoperative coronary artery bypass grafting is effective, but has an increased operative mortality and morbidity, especially in patients with unstable angina, left main stem stenosis and poor preoperative left ventricular function.