Ethnic diversity: South Asian ethnicity is associated with increased coronary artery bypass grafting mortality

Abstract

South Asian ethnicity might result in a higher atherosclerotic vascular risk compared with white ethnicity. However, the effect of South Asian ethnicity on clinical outcomes after cardiac surgery is unknown. Thus, we determined whether South Asian ethnicity is a predictor of a poorer outcome after coronary artery bypass grafting. We examined data from 6177 South Asian and white patients who underwent coronary artery bypass grafting at the Toronto General Hospital from January 1994 through June 2003 and used propensity score matching techniques to analyze 917 patients from each group in more detail. Patients were matched for age, sex, body surface area, left ventricular ejection fraction, New York Heart Association class, previous cardiac surgery, number of diseased vessels, and other factors. Independent predictors of operative morbidity and mortality were determined by means of multivariate logistic regression. Overall operative mortality was 1.8%. Mortality was higher in South Asian patients than in white patients (2.5% vs 1.1%, P = .02). Postoperative morbidity (eg, myocardial infarction, sepsis, sternal wound infection, postoperative hospital stay, and use of inotropes) also was higher in the South Asian group. In addition to the standard independent predictors of mortality, South Asian ethnicity was an independent predictor of mortality (odds ratio, 3.1; 95% confidence interval, 1.4-6.8). These data indicate that South Asian ethnicity per se is an independent predictor of a poorer outcome after coronary artery bypass grafting and suggest that ethnicity is a cardiovascular risk factor that should be considered when assessing clinical outcomes preoperatively before coronary artery bypass grafting or other interventional revascularization procedures.