[Coronary artery surgery after 70 years: an analysis of the risk factors of operative mortality].

The risk factors of operative mortality after coronary bypass surgery in patients over 70 years of age were studied in a consecutive series of 109 patients operated in our department between January 1990 and June 1992. The anginal pain was classified stage III or IV in 92 cases. Seventy-nine patients had triple vessel disease, 36 patients had left main stem stenosis and 57 had previous myocardial infarction. Twenty-six patients had ejection fractions of less than 50% and 6 were less than 30%. The average number of bypass grafts was 2.35. Associated procedures included 9 endarteriectomies of the left main coronary, one endarteriectomy of the left anterior descending and right coronary arteries, 2 myotomies involving the left anterior descending artery, 3 ventricular remodeling procedures and 3 carotid endarteriectomies. Non-lethal postoperative complications were mainly pulmonary infections (19 cases). The operative mortality was 5.1% in the group with stable angina. On the other hand, the mortality was 31.2% in the group with unstable angina operated as an emergency or semi-emergency. The causes of death were mainly postoperative low output states (16 cases) and polyarteriopathy (mesenteric infarction: 6 cases). Although age was related to operative risk, the main prognostic factor was the preoperative cardiovascular status. The degree of emergency, unstable angina, left main coronary disease, duration of cardio-pulmonary bypass and the necessity for inotropic or mechanical support in the postoperative phase were significant risk factors for death. Sex, cardiovascular risk factors, previous myocardial infarction and duration of aortic clamping were not correlated to mortality.(ABSTRACT TRUNCATED AT 250 WORDS)