SPECTRUM OF LEFT MAIN CORONARY-ARTERY DISEASE - VARIABLES AFFECTING PATIENT SELECTION, MANAGEMENT, AND DEATH

Abstract

Patients (178) having a diagnosis of left main coronary artery stenosis were divided into 3 groups: surgical, Group I (135); operable medically treated, Group II (21); and inoperable, Group III (21). Groups I and II were comparable with regard to clinical profile, extent of anatomic coronary disease and left ventricular function. Inoperable patients had a higher incidence of prior myocardial infarction (especially anterior) more severe distal coronary disease and markedly depressed left ventricular function. The hospital mortality rate for surgical patients was 4% (6/135). The late mortality rate (median follow-up = 23.4 mo.) was 7% (9/135). For operable patients the late mortality rate was 43% (9/21) at 28 mo. In the inoperable group the late death rate at 20 mo. was 59% (13/22). Actuarial survival at 24 mo. for the 3 groups was 88%, 66% and 42%, respectively. Of the 9 patients who died in the operable group 2 had < 75% obstruction of the left main coronary artery and 2 had normal left ventricular wall motion. Although patients with higher grades of left main coronary artery stenosis and reduced left ventricular function are at greater risk patients with less obstruction and good left ventricular function are at risk and should have myocardial revascularization with some sense of urgency. The population of left main coronary artery stenosis is a heterogeneous one and comparison of surgical vs. medical therapy should exclude inoperable patients. The operative mortality rate was greatly reduced in recent years (2% in the last 100 cases); this is attributed to careful monitoring in the critical prebypass period, aggressive pharmacologic treatment of increased preload, tachycardia and hypertension and improved surgical technique with emphasis on careful myocardial preservation. Adherence to these principles makes frequent use of the intra-aortic balloon before or after revascularization unnecessary.