[Operative risk in coronary bypass. A multivariate analysis of prognostic factors]

In order to determine the predictors of operative risk in coronary bypass surgery, we have studied 2112 consecutive patients who underwent isolated coronary bypass surgery between January 1979 and September 1984. The overall operative mortality (OM) was 4.4 percent (3.5 percent during the last 3 years). OM increases significantly with age (from O before the age of 30 to 12.3 percent after 70), the functional class (FC) of angina, the FC of dyspnea (NYHA), the creatinine blood level (23.5 percent if greater than 200 mumol/l), the left ventricular end-diastolic pressure and in case of reoperation (16.7 percent), as well as in women (11.6 percent). There is a trend toward higher OM in case of past history of ventricular tachycardia or arterial hypertension, atherosclerotic disease of the lower extremities, left ventricular dysfunction or severe stenosis of the left main coronary artery. OM is not increased in patients with multivessel disease, diabetes or with a past history of myocardial infarction, and is even decreased in obese patients. The variables selected by multivariate analysis were: creatinine blood level, then angina FC, sex, dyspnea FC, age, the absence os obesity, left ventricular dysfunction, the year of surgery and finally reoperation. These results, mainly based on simple clinical variables, should facilitate the therapeutic decisions in borderline indications of coronary bypass surgery.