Multivariate analysis of the long-term results of coronary artery bypass grafting performed during 1976 and 1977.

The results of 492 consecutive coronary artery bypass grafting operations performed for angina in the 2-year period from 1976 to 1977 were evaluated 77 months after surgery. Follow-up was complete in 99%. In 80% of patients angina severity was New York Heart Association functional classes III or IV. An ejection fraction of less than 50% and left ventricular end-diastolic pressure of more than 15 mm Hg were each present in one-third of patients. Thirteen patients (2.6%) died in hospital and 70 (14%) died later during the follow-up period. Twenty-six reoperations were performed for recurrent angina (5.3%). Angina was initially relieved by operation in 97% of patients, but only 57% were alive and free of angina 6 years after their operation. Despite this, 91% of patients at last follow-up were in functional class I or II and 94% thought their symptoms were better than preoperatively. The mean postoperative time of onset of angina, estimated independently by family physicians and patients, was 33 months. The significant preoperative predictors of late death were a low left ventricular ejection fraction, previous myocardial infarction, prior cardiac surgery, increased cardiothoracic ratio and the number of coronary arteries with significant narrowing.