Race/ethnicity and the incidence of new-onset atrial fibrillation after isolated coronary artery bypass surgery

Background: Atrial fibrillation (AF) is more prevalent in Caucasians than in persons of other racial/ethnic groups.

Objective: The purpose of this study was to examine the association between race/ethnicity and new-onset postoperative atrial fibrillation (POAF) after coronary artery bypass grafting (CABG).

Methods: Data from all patients with no history of AF who underwent isolated CABG at our institution from 2000 through 2008 were analyzed. Univariate analyses of preoperative and perioperative variables were performed to identify predictors of POAF. Multivariate stepwise logistic regression was performed to determine independence. Propensity-score matching was used to assess racial/ethnic differences in POAF risk.

Results: Of the 5,823 patients (mean age 72 ± 11 years; 75.5% male) included in the study, 3,966 (68%) were Caucasian (mean age 65 ± 10 years; 77.9% male). The incidence of POAF was 28.9% (1,683/5,823) overall; 32.4% (1,287/3,966) in Caucasians and 21.3% (396/1,857) in non-Caucasians. Multivariate logistic regression revealed that Caucasian race/ethnicity independently predicted POAF (odds ratio [OR] 1.8, 95% confidence interval [CI] 1.5-2.0; P <.0001). The propensity-matching analysis of 715 Caucasians and 715 non-Caucasians confirmed Caucasian race/ethnicity as an independent predictor of POAF (OR 1.7, 95% CI 1.3-2.2; P <.001). Other independent predictors were obesity (OR 1.4, 95% CI 1.0-2.0; P = .04), congestive heart failure (OR 1.8, 95% CI 1.3-2.6; P = .0002), and age 50-59 years (OR 3.7, 95% CI 1.7-8.3; P = .0006), with increasing risk for each additional increment of 10 years.

Conclusion: Caucasians are at higher risk for POAF after isolated CABG than are persons of other races. Race probably is a surrogate for unrecognized variables such as genetic disparities among racial/ethnic groups.