Coronary Bypass Surgery for Unstable Angina Pectoris

The first 81 patients to undergo coronary artery bypass surgery for unstable angina pectoris at Standford Hospital have been observed for a mean of 40.8 months. Surgical mortality was 8.5%, and perioperative incidence of myocardial infection was 16%. The mean 18-month follow-up showed two early cardiac deaths and 12 additional myocardial infarctions. Sixty-seven percent of the patients were angina-free, and the condition of none was worse. After a mean of 40.8 months, two late cardiac deaths and two myocardial infarctions had occurred. Complete relief of angina was present in 51%;22% had unstable or worsening angina. The probability of survival from time of operation to four months after surgery was 88.8% +/- 3.5%, and this remained unchanged until the two late deaths, which decreased survival probability to 83.8% +/- 4.8% at 43 months. The two late cardiac deaths and the 22% incidence of patients with worsening angina may reflect progression of the atherosclerotic process, late graft occlusion, or both.