Factors affecting suitability for coronary bypass surgery.

Factors responsible for unsuitability for bypass surgery were assessed prospectively in 324 consecutive patients with serious angina pectoris undergoing cardiac catheterization. One hundred patients were found to be unsuitable for surgery (31%). These patients usually had peripheral coronary atherosclerosis (44%), stenotic/occluded artery distributing to an infarcted (35%) or small area (25%), or reduced global left ventricular (LV) function (15%). Age over 65 years (p less than 0.05), female sex (p less than 0.05), previous myocardial infarction (p less than 0.05), 1-vessel disease (p less than 0.01) and a low LV ejection fraction (p less than 0.01) occurred more often in patients not accepted for surgery. Of the patients with 3-vessel disease 75% were referred for surgery while only 25% of patients with 1-vessel disease (p less than 0.001) Stepwise logistic regression analysis identified LV ejection fraction as an inverse predictor (p less than 0.001) and number of stenotic coronary arteries as a predictor (p less than 0.001) of suitability for surgery. Thus, peripheral coronary atherosclerosis and global LV function are the main factors determining unsuitability for coronary bypass surgery.