Survival, myocardial infarction, and employment status in a prospective randomized study of coronary bypass surgery

This report from the European Prospective Randomised Study presents 8 year results on survival and 5 year results on myocardial infarction and employment status. The 768 recruited patients were all men under age 65 with mild or moderate angina, 50% or greater stenosis in at least two major coronary arteries, and a left ventricular ejection fraction of 50% or greater. One "surgical" patient was lost to follow-up immediately after randomization and is therefore excluded from the statistical analysis. Thus 394 patients allocated to surgery were compared with 373 patients allocated to medical treatment, regardless of what subsequently happened to the patients. The policy of early surgery improved survival significantly compared with the conventional medical treatment policy in the total population (89% to 80%, respectively; p = .0013) and in the subgroup with three-vessel disease (92% and 77%, respectively; p = .00015). Reclassification of vessel disease by greater than 75% instead of 50% or greater stenosis as the criterion was undertaken to facilitate comparison of these results with those of other studies, which apply 70% or greater stenosis as the criterion of significant disease. Of the 767 patients, a cohort of 711 were identified as having greater than 75% obstruction in one, two, or three vessels. A significant improvement in survival with surgery was found in the total cohort (89% and 80%, respectively; p = .0022), the subgroup with three-vessel disease (91% and 73%, respectively; p = .0044), and that with two-vessel disease in which one of the diseased vessels was the proximal segment of the left anterior descending artery (LAD) (90% and 79%, respectively; p = .013). There was no significant difference in survival between the two treatments in patients with one-vessel disease and those with two-vessel disease without proximal LAD stenosis. Four noninvasive prognostic variables were independently predictive of the effect of surgery: resting electrocardiogram (in 767 patients), ST segment response to exercise (in 656), history and physical signs of peripheral arterial disease (in 722), and age (in 767). A reduction in cardiac deaths was entirely responsible for the improved survival with surgery. The incidence of myocardial infarction in the medical group (11%) was not significantly different from that in the surgical group (15%). Repeat angiography in 71 patients showed 6% graft closure between 1 and 5 years of follow-up. Surgery did not influence the gradually increasing annual rate of retirement from work.