Assessment of independent predictors for long-term mortality between women and men after coronary artery bypass grafting: are women different from men?

Objective: The long-term mortality of coronary artery bypass grafting in women in not certain. The purpose of this study was to determine and compare risk factors for long-term mortality in women and men undergoing coronary artery bypass grafting.

Methods: Between 1992 and 2002, 3760 consecutive patients (2598 men and 1162 women) underwent isolated coronary artery bypass grafting. Long-term survival data were obtained from the National Death Index (mean follow-up, 5.1 +/- 3.2 years). Multivariable Cox regression analysis was performed, including 64 preoperative, intraoperative, and postoperative factors separately in women and men.

Results: There were no differences in in-hospital mortality (2.7% in men vs 2.9% in women, P = .639) and 5-year survival (82.0% +/- 0.8% in men vs 81.1% +/- 1.3% in women, P = .293). After adjustment for all independent predictors of long-term mortality, female sex was an independent predictor of improved 5-year survival (hazard ratio, 0.82; 95% confidence interval, 0.71-0.96; P = .014). Twenty-one independent predictors for long-term mortality were determined in men, whereas only 12 were determined in women. There were 9 common risk factors (age, ejection fraction, diabetes mellitus, > or =2 arterial grafts, postoperative myocardial infarction, deep sternal wound infection, sepsis and/or endocarditis, gastrointestinal complications, and respiratory failure); however, their weights were different between women and men. Malignant ventricular arrhythmias, calcified aorta, and preoperative renal failure were independent predictors only in women. Emergency operation, previous cardiac operation, peripheral vascular disease, left ventricular hypertrophy, current and past congestive heart failure, chronic obstructive pulmonary disease, body mass index of greater than 29, preoperative dialysis, thrombolysis within 7 days before coronary artery bypass grafting, intraoperative stroke, and postoperative renal failure were independent predictors only in men.

Conclusions: Despite equality between sexes in early outcome and superiority of female sex in long-term survival, there were 3 independent predictors for long-term mortality after coronary artery bypass grafting unique for women compared with 12 for men. Clinical decision making and follow-up should not be influenced by stereotypes but by specific findings.