Left main stem coronary artery disease. Retrospective review of 26 patients treated surgically or medically.

The clinical, angiographic, exercise testing, operative, and follow-up data of 26 patients found at angiography to have left main stem coronary artery stenosis, defined as a reduction in the lumen diameter of 50% or more, are reviewed. There was a high incidence of significant proximal stenosis in the branches of the left main stem. No clinical features were found to distinguish patients with left main stem stenosis. All patients were considered for saphenous vein bypass grafting, selection being based upon the severity of symptoms, left ventricular function, and suitability of the coronary vessels for grafting. Two patients died within 24 hours of coronary angiography. Nine patients were operated on with no mortality. There has been one late cardiac death during a mean follow-up time of 13 months. All patients were symptomatically improved with a significant (P less than 0-01) increase in exercise ability postoperatively. Fifteen patients were not operated on. Six of these patients were regarded as operable but surgery was deferred; five have died at a mean time of 7-2 months. Five of the nine patients regarded as inoperable have died at a mean follow-up time of 14-8 months. The five non-surgical survivors remain symptomatic with no significant change in exercise ability. Recently reported surgical and medical series of patients with left main stem stenosis are reviewed.