Prospective randomized study of coronary bypass surgery in stable angina. The first 100 patients

In a prospective study to evaluate surgery for angina pectoris, 50 patients randomized to surgery and 50 treated medically have completed 8 to 34 months' follow-up (median, 24 months). Anginal symptoms improved in both groups (88%, 72%), but more operated patients are currently asymptomatic (70%, 8%) and using fewer medications (nitrates, 18%, 96%; propranolol, 8%, 72% of patients). Exercise tests with treadmill revealed increased exercise tolerance time in both groups, more so in the operated group (+ 89%, + 42%), and angina could not be provoked in 70% and 20% of patients, respectively. During the follow-up, fewer cardiac complications developed in the operated group (19 vs. 44; P = less than 0.02); there was no difference in mortality. Repeat catheterization in 83 of 84 survivors at 1 year did not reveal any significant differences in the progression of disease. Atrial pacing studies revealed improvement in anginal threshold in 70% of operated and 48% of nonoperated patients. The study suggests that although subjective and objective improvement occurs with surgical as well as nonsurgical treatment, the frequency and magnitude are higher with surgery. The quality of life appears to be better in the operated patients during the first 24 months. Further follow-up is necessary to determine the duration of such improvement and to assess the influence of surgery on the natural life history of this disease.