Clinical, anatomic and functional descriptors influencing morbidity, survival and adequacy of revascularization following coronary bypass

Abstract

Clinical data on 3,479 consecutive patients having coronary bypass surgery were retrospectively analyzed. Perioperative complications, incomplete revascularization, and reduced long-term survival could frequently be correlated with manifestations of myocardial damage. Patients with triple vessel and left main coronary disease had a greater frequency of inotropic requirements than did patients with single or double vessel disease (7.9% and 8.6% vs. 3.8% and 4.2%). Inotropic requirements in the perioperative period were significantly increased for patients with preoperative left ventricular dysfunction; a history of heart failure or multiple infarctions did not significantly increase the incidence of inotropic requirements. Presence of previous myocardial infarction, heart failure, or left ventricular contraction abnormalities significantly decreased the ability to achieve complete revascularization with bypass grafting. Hospital mortality since 1976 has been 0.8% (25/3,040). Hospital mortality was significantly increased by history of myocardial infarction, hypertension, heart failure, extent of anatomic disease, presence of preoperative ST-T wave changes, and severe abnormalities of left ventricular function. Hospital mortality in patients with ejection fraction </=0.35 was 3.4% vs. 1.3% for those >0.35. Anginal pattern, history of hypertension, previous myocardial infarction, preoperative heart failure all significantly affected long-term survival. Occurrence of perioperative myocardial infarction did not adversely influence long-term survival. Patients with normal left ventricular function had excellent 42 month survival regardless of vessel disease (95%, 96%, and 94% for single, double, and triple vessel disease, respectively). Survival was significantly less for such patients with abnormal left ventricular function. Inability to achieve complete revascularization did not adversely affect hospital mortality, but did significantly reduce late survival. The important effect which complete revascularization had on long-term survival appeared to increase with increasing severity of coronary disease. Although bypass grafting improves survival in patients with multivessel disease and left ventricular dysfunction, the benefits appear to be significantly reduced once manifestations of left ventricular damage have occurred.