Off-Pump Techniques Disproportionately Benefit Women and Narrow the Gender Disparity in Outcomes After Coronary Artery Bypass Surgery

Background—Women experience greater morbidity and mortality than men after conventional coronary artery bypass grafting (CABG) on cardiopulmonary bypass (CPB). The objective of this study was to determine whether off-pump CABG (OPCAB) alters this gender-based disparity. Methods and Results—Retrospective review of risk factors and clinical outcomes for 11 413 consecutive patients having isolated CABG between January 1, 1997, and May 31, 2005, at a US academic center. Interventions were OPCAB or CABG/CPB, performed at the discretion of 14 faculty surgeons. Main outcome measures included in-hospital death, stroke, myocardial infarction or combined major adverse cardiac events (MACEdeath or stroke or myocardial infarction). Odds ratios of adverse events, adjusted for 31 risk factors, were compared between women and men who had OPCAB versus CABG/CPB. Covariates included Propensity Score, Society of Thoracic Surgeons ’ Predicted Risk, surgeon and body habitus. Female patients (n3248) and those treated with OPCAB (n4492) were older, had more comorbidities and higher predicted risk than male patients (n8165) and those treated with conventional CABG/CPB (n6921), respectively. Women treated with CABG/CPB had a risk-adjusted odds ratio of 1.60 for death (P0.01), 1.71 for stroke (P0.007), 2.26 for myocardial infarction (P0.008) and 1.71 for MACE (P0.001) compared with men who had CABG/CPB. In contrast, women treated with OPCAB had outcomes statistically similar to men who had either OPCAB or CABG/CPB. Among women, OPCAB was associated with a significant reduction in death (OR 0.39