European Ancestry as a Risk Factor for Atrial Fibrillation in African Americans

• Published in: Circulation (New York, N.Y.) Vol. 122; no. 20; pp. 2009 - 2015
• Main Authors: MARCUS, Gregory M, ALONSO, Alvaro, DEO, Rajat, SOTOODEHNIA, Nona, AKYLBEKOVA, Meggie, ELLINOR, Patrick T, PALTOO, Dina N, SOLIMAN, Elsayed Z, BENJAMIN, Emelia J, HECKBERT, Susan R, PERALTA, Carmen A, LETTRE, Guillaume, VITTINGHOFF, Eric, LUBITZ, Steven A, FOX, Ervin R, LEVITZKY, Yamini S, MEHRA, Reena, KERR, Kathleen F
• Format: Journal Article
• Language: English
• Published: Hagerstown, MD Lippincott Williams & Wilkins 16-11-2010
• Subjects: Aged; Atrial Fibrillation - epidemiology; Atrial Fibrillation - genetics; Atrial Fibrillation - physiopathology; Biological and medical sciences; Black or African American - genetics; Blood and lymphatic vessels; Cardiology. Vascular system; Coronary heart disease; Diseases of the peripheral vessels. Diseases of the vena cava. Miscellaneous; Female; Genome-Wide Association Study; Heart; Humans; Male; Medical sciences; Middle Aged; Risk Factors; White People - genetics; ancestry; genetics; Arrhythmia; Heart disease; Atrial fibrillation; Risk factor; African Americans; Cardiovascular disease; Excitability disorder; African American
• ISSN: 0009-7322; 1524-4539; 1524-4539
• DOI: 10.1161/circulationaha.110.958306

Despite a higher burden of standard atrial fibrillation (AF) risk factors, African Americans have a lower risk of AF than whites. It is unknown whether the higher risk is due to genetic or environmental factors. Because African Americans have varying degrees of European ancestry, we sought to test the hypothesis that European ancestry is an independent risk factor for AF.
We studied whites (n=4543) and African Americans (n=822) in the Cardiovascular Health Study (CHS) and whites (n=10 902) and African Americans (n=3517) in the Atherosclerosis Risk in Communities (ARIC) Study (n=3517). Percent European ancestry in African Americans was estimated with 1747 ancestry informative markers from the Illumina custom ITMAT-Broad-CARe array. Among African Americans without baseline AF, 120 of 804 CHS participants and 181 of 3517 ARIC participants developed incident AF. A meta-analysis from the 2 studies revealed that every 10% increase in European ancestry increased the risk of AF by 13% (hazard ratio, 1.13; 95% confidence interval, 1.03 to 1.23; P=0.007). After adjustment for potential confounders, European ancestry remained a predictor of incident AF in each cohort alone, with a combined estimated hazard ratio for each 10% increase in European ancestry of 1.17 (95% confidence interval, 1.07 to 1.29; P=0.001). A second analysis using 3192 ancestry informative markers from a genome-wide Affymetrix 6.0 array in ARIC African Americans yielded similar results.
European ancestry predicted risk of incident AF. Our study suggests that investigating genetic variants contributing to differential AF risk in individuals of African versus European ancestry will be informative.