Left main coronary artery obstruction. Follow-up of thirty patients with and without surgery.

Thirty patients, 20 males and 10 females, having a 50% or greater obstruction of the left main coronary artery, were evaluated. Their ages ranged from 40 to 71 years (mean 53.8 years). All patients had angina pectoris, the duration of which varied from 2 months to 20 years (mean 5.4 years). Twenty-four patients (80%) had accelerated angina pectoris; 17 (56.7%) had prior myocardial infarction, and 27 (90%) were found to have coexisting three-vessel disease and abnormal left ventricular contraction. There were no deaths or serious arrhythmias related to cardiac catheterization procedures. In the 11 unoperated patients 5 (45%) died within the first year of follow-up; however, all except one death occurred in patients with diffuse distal coronary artery disease technically unsuitable for surgery. Among the six survivors four were considered surgical candidates. These four patients have continued to have symptoms of angina pectoris with a mean follow-up period of 17.5 months (16 to 20 months). In the 19 patients who underwent aortocoronary saphenous vein bypass grafting, there was one immediate postoperative death (surgical mortality 5.3%) and one late death. The 17 survivors in the surgical group have a mean follow-up period of 17.3 months (8 to 31 months); 13 of them have clinically improved with 6 being totally free of angina pectoris. Thus, mortality is extremely high in those with poor distal vasculature technically unsuitable for surgery, but mortality is relatively low in patients who have technically bypassable lesions whether treated surgically or medically. Although saphenous vein bypass grafting appears to be more effective in providing clinical improvement, asymptomatic left main coronary obstruction may not justify surgical therapy.