Abstract 16742: Asians, Hispanics, and Blacks Exhibit Similar Reductions in Incident Atrial Fibrillation

Abstract

Introduction Despite a higher burden of risk factors, Blacks experience lower rates of atrial fibrillation (AF) compared to Whites. Identifying the mechanisms responsible for this association may guide future research regarding AF pathogenesis, treatment, and prevention. Because it is unknown whether White race increases AF risk or Black race affords AF protection, we evaluated incident AF among multiple racial and ethnic groups. Hypothesis Asians, Hispanics, and Blacks each demonstrate reduced incident AF compared to Whites. Methods Using Healthcare Cost and Utilization Project data, we identified patients ≥ 50 years of age who received care in a California hospital setting between January 1, 2005 and December 31, 2009. Those with non-California residence and prevalent AF were excluded. Race/ethnicity was defined by the discharging institution. AF and other medical comorbidities were identified using ICD-9 codes. After an index encounter, patients were observed until AF diagnosis, death, or the end of the study period. Cox proportional hazard models with time dependent covariates were used to compare the adjusted risk of incident AF. Results Among 6,155,960 patients (66% White, 9% Asian, 19% Hispanic, and 6% Black), a total of 353,352 first-time AF events were identified over an average of 3.0 years. Incident AF occurred at a rate of 19.6 (95% CI 19.6-19.7) per 1,000 person-years. After adjusting for potential confounders, each non-White race/ethnicity exhibited a significantly reduced rate of AF compared to Whites (Figure, Asian HR 0.76, 95% CI 0.75 to 0.77; Hispanic HR 0.79, 95% CI 0.78 to 0.80; Black HR 0.82, 95% CI 0.80 to 0.83; p<0.001 for all comparisons). Conclusions White patients are at increased risk of AF as compared to Asians, Hispanics, or Blacks. These findings argue against a protective effect unique to Black race and instead suggest unidentified factors associated with White race increase AF risk.