Abstract 21153: The Atrial Fibrillation Ethnic Paradox: Insights From National Inpatient Sample Database

Abstract

Introduction: It has been reported that African-American (AA) patients have lower incidence of atrial fibrillation (AF) as compared to their Caucasian (C) counterparts. However, precise differences in incidence of the traditional risk factors in the above groups have not been described in large population cohorts. Hypothesis: To confirm and further delineate previously reported ethnic trends in AF patients amongst AA and C. Methods: We retrospectively analyzed 8,080,123 hospitalized patients between the years 2011-2013 from the National Inpatient Sample database. All patients with a principal diagnosis of AF based on ICD-9-CM code of 427.31 (n = 932,303, 11.5%) formed the study cohort and were further sub-categorized into C and AA cohorts. Chi-square and one-sample T test were used to compare the traditional risk factors between AA and C patients with AF. Results: AF incidence in C was 12.9% vs 5.5% in AA (p < 0.001). AA were younger (69.57 ± 28.49 years vs. 76.81 ± 23.2 years, p < 0.05 ) and had less men (46.6% vs. 49.9%). AAs had higher prevalence of hypertension (75.9% vs. 70%), congestive heart failure (26.5% vs. 23.3%), diabetes mellitus with (8.4% vs 5.3%) or without complications (33% vs. 25.2%), renal failure (35.5% vs. 22.2%), obesity (16.6% vs. 11.8%), smoking (8.4% vs 6%) and alcohol consumption (3.9% vs. 2.7%). C however had a higher prevalence of coronary atherosclerosis (41.7% vs 35.9%). All of the above were statistically significant with a p-value < 0.001 with 95% confidence intervals. Conclusion: Our data demonstrates a significant AF ethnicity paradox. Despite higher prevalence of traditional risk factors for AF, AA had >2-fold lower incidence of AF compared to Cs. Possible hypothesis for the above includes under-diagnosis of AF in AA, age differences, or yet unknown pathophysiological features of AF. While the former can be addressed with vigilant clinical practice, the latter would need further research.