Left Main Coronary Artery Stenosis

Fifty-six patients with severe stenosis of the left main coronary artery underwent coronary bypass surgery between January 1970 and December 1971. All patients had angina pectoris. Seventy-five per cent of the patients had an unstable anginal pattern. There were six perioperative deaths for a surgical mortality of 10.7%. Of the 50 patients surviving surgery, 96% are alive from 12 to 36 months postoperatively, 90% have had a significant reduction in anginal symptoms and 76% are asymptomatic. Postoperative catheterization studies, performed one to 28 months after surgery in 31 patients, showed that 83% of 75 bypass grafts were widely patent. In each patient studied there was at least one widely patent graft to the left coronary artery. Six patients had exercise studies using supine bicycle ergometry during pre- and postoperative cardiac catheterization. These studies demonstrated improvement in exercise tolerance and in left ventricular hemodynamics after coronary surgery.