Racial Disparity Persists After On-Pump and Off-Pump Coronary Artery Bypass Grafting

Abstract

Background— Race has been shown to be an independent risk factor for operative mortality after coronary artery bypass grafting (CABG). This study sought to determine the extent to which race is a risk factor for adverse events, long-term mortality, and whether off-pump surgery (OPCAB) modifies that risk. Methods and Results— The Society of Thoracic Surgeons Adult Cardiac Database at Emory Healthcare affiliated hospitals was queried for all primary isolated CABG records from 1997 to 2007. A propensity score was formulated to balance the patient groups with respect to treatment assignment (OPCAB or CABG on cardiopulmonary bypass). Multivariable logistic regression was used to assess the impact of black race and OPCAB on in-hospital outcomes (death, stroke, myocardial infarction, and their composite, major adverse cardiac events). Cox proportional hazards regression model and Kaplan–Meier curves determined whether black race affected long-term all-cause mortality. Interaction terms were constructed to test whether OPCAB surgery influences surgical results differently in black patients than in white patients. There were 12 874 consecutive CABG patients, including 2033 (15.8%) blacks and 10 841 (84.2%) whites. Survival at 3, 5, and 10 years for blacks (87.5%, 81.4%, 63.8%) was significantly lower than for whites (90.7%, 85.2%, 67.1%, P <0.001). Blacks (adjusted odds ratio, 0.77; 95% CI, 0.44 to 1.36) and whites (adjusted odds ratio, 0.72; 95% CI, 0.53 to 0.99) who had OPCAB had lower risk-adjusted odds of major adverse cardiac events than their racial counterparts who had CABG on cardiopulmonary bypass. Conclusions— Short- and long-term outcomes are significantly worse in black than in white patients undergoing primary isolated CABG. OPCAB does not narrow the disparity in outcomes between blacks and whites.