Is Gender an Independent Risk Factor for Coronary Bypass Grafting?

BACKGROUND: Postoperative mortality after coronary artery bypass grafting (CABG) surgery is traditionally considered to be influenced by gender. However, the data are conflicting and it is not clear whether gender is a true independent risk factor for death in this setting. We analyzed our database to determine whether gender is an independent risk factor for death after CABG. PATIENTS AND DESIGN: A retrospective analysis of 1 758 isolated first-time coronary artery bypass graft patients treated between 2003 and 2005 was conducted in the Department of Cardiothoracic Surgery of Rabin Medical Center, a major tertiary facility in Israel. RESULTS: The female patients had a distinctly different pre- and intraoperative profile compared with the male patients, and significantly higher postoperative mortality (p < 0.05). On a propensity scoring of 359 matched pairs, the risk factors for death were found to be severe left ventricular dysfunction, chronic obstructive pulmonary disease, and use of an intra-aortic balloon pump (p < 0.05). The addition of intraoperative data to the model yielded only cardiopulmonary bypass time and use of an intra-aortic balloon pump as risk factors for death (p < 0.05). Validation with the bootstrap technique revealed that strong predictors of death (> 50 % of the sample) were cardiopulmonary bypass time, use of an intra-aortic balloon pump, and, to a lesser extent, chronic obstructive pulmonary disease. Female gender was not found to be an independent risk factor for death after coronary artery bypass graft. CONCLUSIONS: Female gender is apparently not an independent risk factor for coronary artery bypass graft mortality in this patient group.