Effects of race, with or without gender, on operative mortality after coronary artery bypass grafting: A study using the Society of Thoracic SurgeonsNational Database

Background. Although gender is known to be an independent predictor of 30-d ay operative mortality (OM) after coronary artery bypass grafting, the purp ose of this study was to determine whether race-alone or in combination wit h gender-affects OM. Methods. For 1994 to 1996, The Society of Thoracic Surgeons database record s for 441,542 coronary artery bypass grafting-only procedures were analyzed . Baseline annual multivariate models were built. Gender and race were adde d to each model. Risk-adjusted OM rates were then calculated for race, gend er, and their combination. Patients were also stratified into groups of com parable predicted OM to allow for a direct comparison of risk-matched Cauca sians and non-Caucasians. Results. Of the procedures, 28.2% were on women and 8.5% on non-Caucasians. Overall, OM was 3.29%. Multi-variate risk-adjusted OM varied by gender and race (p < 0.10). Risk-adjusted OM rates (with 95% confidence intervals) we re 4.0% (3.9% to 4.1%) for females and 3.2% (3.2% to 3.3%) for males. Risk- adjusted OM rates were 3.9% (3.7% to 4.1%) for non-Caucasians and 3.3% (3.2 % to 3.3%) for Caucasians. Among equally risk-matched Caucasians and non-Ca ucasians, non-Caucasians had significantly higher (p < 0.005) mortality amo ng the lower risk subgroups (up to 10% predicted OM) but not among the high er risk subgroups. Conclusions. Race and gender are independent predictors of adverse outcome following coronary artery bypass grafting, holding all other risk factors c onstant. (C) 2001 by The Society of Thoracic Surgeons.