Three large cooperative randomized trials have evaluated the effects of medical and surgical management of ischemic heart disease on survival and other secondary end points. Both randomized and observational data from these trials show increased survival following coronary artery bypass grafting (CABG) in patients with left main coronary artery stenosis, triple-vessel disease, double-vessel disease, left ventricular (LV) functional impairment, or LV aneurysm. The incidence of fatal, but not nonfatal, myocardial infarction is reduced by CABG. Results in patients 65 years of age or older are similar to those in younger patients but are influenced by associated disease. Gainful employment and risk factors are uninfluenced by treatment. Symptoms of congestive heart failure were not improved by CABG alone but were improved by LV aneurysmectomy when this was performed.