Aortocoronary artery bypass: present indications and risk factors.

From 1969 through 1974, a total of 4,522 patients were operated on for coronary artery occlusive disease. This article is an in-depth analysis of a consecutive series of 275 of these patients, operated on during 1974. The mortality was 1.8% and perioperative myocardial infarction occurred in 3.6%. On analysis of risk factors, it was found that 24% of the patients were over the age of 60; 57% had some degree of left ventricular dysfunction; 9% had generalized hypokinesis; 24% were New York Heart Association functional class IV; 13% had left main coronary artery stenosis; and 11% had preinfarction angina. On analysis of the early mortality, the limiting factor was diffuse coronary arteriosclerosis combined with poor ventricular function. This resulted in inadequate or incomplete myocardial revascularization. Since these two risk factors are usually predictable, coronary artery bypass can be recommended not only for patients with intractable angina, but also for patients with impaired left ventricular function associated with angina, and in patients without angina who have a positive stress electrocardiogram.