Abstract 15821: Atrial Fibrillation Incidence in Hispanics Compared to Non-Hispanic Blacks, Chinese, and Whites and the Impact of Atrial Fibrillation Risk Factors: The Multi-Ethnic Study of Atherosclerosis

Abstract

BACKGROUND: Reportedly, non-Hispanic blacks have a lower atrial fibrillation (AF) burden compared with their non-Hispanic white counterparts. Information on the epidemiology of AF in Hispanic and Asian populations is much more limited. We studied incident AF in the Multi-Ethnic Study of Atherosclerosis (MESA).

METHODS: We excluded participants with a history of AF at enrollment. 6,721 MESA participants were monitored for the first AF event ascertained according to hospital discharge ICD-9 codes. The incidence rate (IR) of AF was calculated per 1000 person-years of observation. Incidence rate ratios (IRR) were calculated using non-Hispanic whites as the reference group. Unadjusted population attributable fractions of established AF risk factors (baseline hypertension and diabetes status) were ascertained.

RESULTS: 47.2% of the MESA cohort was male; 25.7% had hypertension; 12.5% had diabetes. 305 incident AF events occurred over a mean follow up of 7.3 years. Age and sex adjusted IRs and IRRs showed that overall AF incidence was significantly lower among Hispanics, non-Hispanic blacks and Chinese compared to non-Hispanic whites (all p<0.001). (Table) Among older age groups (>65 years old), Hispanics, Chinese and Blacks had significantly lower AF event rates than non-Hispanic whites (all p<0.01). Differences among the younger age groups did not reach statistical significance. The proportion of AF events attributable to diabetes was lowest among whites (4.7%) and highest among Hispanics (19.5%). Among non-Hispanic whites, 34.5% of AF events were attributable to hypertension. This figure was higher among non-Hispanic blacks (49.9%), Chinese (55.7%), and Hispanics (53.9%).

CONCLUSIONS: The incidence of AF in Hispanics is significantly less than in non-Hispanic whites and similar to that seen in non-Hispanic blacks. Diabetes appears to be most impactful on AF events among Hispanics.