SURVIVAL AT 15 TO 18 YEARS AFTER CORONARY-BYPASS SURGERY FOR ANGINA IN WOMEN

Background. Coronary bypass surgery in women is associated with lower survival than in men. We need to know whether this is because of patie nt-related factors and whether the lower survival is present in all su bgroups of patients and for all time periods during which the surgery was performed. Methods and Results. Using actuarial techniques, we det ermined the outcome of coronary bypass surgery performed for chronic s table and unstable angina in 1979 women and 6927 men. The operative mo rtality was 2.7% for women and 1.9% for men (P=.02). The higher operat ive mortality in women was seen in those with three-vessel disease or greater and abnormal left ventricular function (5.4% versus 2.8%, P=.0 09) and those with stable angina (2.6% versus 1.5%, P=.006). The 5-, 1 0-, 15-, and 18-year survival for women was 86+/-0.9%, 70+/-1.5%, 50+/ -2.5%, and 37+/-6.4%, respectively, and for men, 88+/-0.4%, 73+/-0.7%, 54+/-1.2%, and 42+/-1.9%, respectively (P=.03). The lower survival in women compared with men was seen in those with three-vessel disease o r greater and abnormal left ventricular function (at 10 years, 53+/-3. 7% versus 65+/-1.6%, P=.0006) and in those with stable angina (at 10 y ears, 69+/-1.8% versus 73+/-0.8%, P=.005). At 15 years, the incidence of reoperation was 26+/-2.4% versus 28+/-1.2% and of myocardial infarc tion, 30+/-2.8% versus 32+/-1.3%, P=NS for either. The incidence of no angina or mild angina was 70% in women and 78% in men, P<.0001. The o perative mortality and late survival of those operated on in different time periods for either women or men was not significantly different. Women were older (64+/-9.4 versus 61+/-9.9 years, P<.0001) and smalle r (body surface area, 2.0+/-0.2 versus 1.7+/-0.2 m2, p<.0001), had a h igher incidence of diabetes, systemic hypertension, and unstable angin a, and had a smaller lumen of the left anterior descending coronary ar tery (1.7+/-0.4 versus 1.9+/-0.4 mm, P<.0001), right coronary artery, and diagonal arteries. More men were smokers, and men had a higher inc idence of prior myocardial infarction, previous coronary bypass surger y, and extent of coronary disease and of abnormal left ventricular fun ction. The Cox regression model of survival showed that independent ri sk factors for lower survival were older age, previous coronary bypass surgery, previous myocardial infarction, and diabetes. Sex was not an independent risk factor for poorer survival. Conclusions. Women have a higher operative mortality and lower long-term survival than men aft er coronary bypass surgery for angina. However, the differences are sm all, even if statistically significant. Importantly, patient-related f actors and not sex are independent predictors of poorer survival. Ther efore, coronary bypass surgery should not be delayed or denied to wome n who have the usual indications for surgery.