Coronary bypass surgery for unstable angina pectoris. Long-term survival and function

J. S. Schroeder, I. Lamb, M. Hu and E. B. Stinson

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.