Coronary bypass surgery in stable angina pectoris. A randomized study of the effects on morbidity, mortality and employment.

The effects of coronary bypass surgery on morbidity, mortality and employment were assessed in a randomized prospective 5-year study. Exercise tolerance showed an immediate, striking improvement, which was maintained throughout the follow-up period. Corresponding patients treated with medical therapy showed no change. More than 40 percent of patients in the surgical group were free from symptoms over the five years. The annual mortality of the surgical patients was 0.8 percent as compared with 4.0 percent in the medical patients (p less than 0.05). The annual mortality of the intensively treated medical patients with multivessel disease was not significantly higher than the 3.1 percent for a group of patients with single-vessel disease followed concomitantly. The rate of work at 5 years after bypass surgery was 47 percent as compared with only 18 percent in the randomized medically treated group (p less than 0.01). It is concluded that coronary bypass surgery reduces morbidity and mortality and improves employment.