Effect of perioperative complications on excess mortality among women after coronary artery bypass: The israeli coronary artery bypass graft study (ISCAB)

Background: Widely observed excess mortality among women after coronary artery bypass grafting is still largely unexplained, although case-mix factors have been identified. We evaluated the contribution of perioperative complications to the risk of 180-day mortality among women while adjusting for case-mix factors. Methods: This is part of a prospective, 1-year nationwide Israeli coronary artery bypass graft study of 1029 female and 3806 male patients. Deaths within 180 days were independently ascertained. Case-mix risk strata were obtained from a pooled Cox survival model (including all subjects and study variables) by using the adjusted coefficients corresponding to the case-mix factors within the model. Sex-specific mortality associated with perioperative complications was evaluated within the strata. In addition, sex-specific Cox models were constructed. Results: Higher mortality among women compared with that among men was significant within the pooled model (hazard ratio, 1.4; P =.038) and was evident early in the postoperative period. Women tended to cluster in the highest risk quartile compared with men (39.8% vs 20.9%, P