Left main coronary artery disease

Abstract Thirty patients with 70 percent or greater obstruction in the left main coronary artery were evaluated during hemodynamic and angiographic studies. There were 25 male and 5 female patients; the average age was 54 years. Twenty-seven patients had moderate to severe angina pectoris, with 14 noting an increase in severity of chest pain within 6 months before arteriography. Six patients also had hemodynamic evaluation by atrial pacing. In each, angina pectoris was easily induced, and all 6 had abnormal pacing ventricular function curves with marked increase in left ventricular end-diastolic pressure associated with a reduction in left ventricular stroke work. Image intensification fluoroscopy revealed calcification in the left main coronary artery in 7 patients. A striking finding was the severity of obstructive disease in the other coronary arteries. Eight patients had total occlusion of the right coronary artery, and 29 of the 30 patients had 2- or 3-vessel disease. Significant coronary arterial collateral vessels were noted in 21 patients. Contraction abnormalities were present in 24 left ventriculograms. Three deaths were associated with cardiac catheterization (mortality rate 10 percent). Only 2 of 18 patients who underwent aortocoronary bypass surgery died. The 16 surgical survivors are in clinically improved condition after a follow-up period of 10 months. Three of 9 patients not operated on have died, all within 1 month of arteriography. Because of the high risk of sudden death, coronary arteriography should be performed with caution in a patient with severe angina pectoris, very positive findings on exercise testing, easily induced angina and heart failure with stress and calcification in the left main coronary artery. After cardiac catheterization all patients should undergo routine monitoring and, when technically feasible, saphenous vein aortocoronary bypass surgery should be performed.