Abstract P439: Ideal Physical Activity is Associated with Reduced Risk of Atrial Fibrillation in African Americans Without Baseline Cardiovascular Disease: the Jackson Heart Study

Background: The effect of physical activity (PA) on incidence of atrial fibrillation (AF) is unclear in African Americans (AA). This study aimed to determine if higher levels of PA are associated with decreased incidence of AF in the Jackson Heart Study (JHS). Methods: Participants of the JHS with PA assessment and without previous AF at baseline were included in the study. PA was categorized based on the American Heart Association physical activity levels. Incident AF was defined as having 12 lead electrocardiogram evidence at a subsequent follow up, or a documented diagnosis code at the time of hospital discharge from 2000 to 2016. Cox proportional hazards models were used to evaluate for the association between baseline PA and incidence of AF. Given significant correlation between PA and baseline cardiovascular disease (CVD), stratified analysis was performed based on CVD status. Results: Of the 4,477 participants followed for a median of 12.5 years, 398 developed AF (7.13 cases per 1,000 person-years). Ideal and intermediate PA were associated with a reduced risk of incident AF compared with poor PA (unadjusted HRs with 95% CIs 0.47 [0.34 - 0.64] and 0.72 [0.58 - 0.90], respectively) (Table). After adjustment for traditional cardiovascular risk factors, the associations attenuated and became no longer significant (0.73 [0.53 - 1.00] and 1.00 [0.80 - 1.25], respectively). In stratified analysis based on baseline CVD status, in participants without baseline CVD, ideal PA was significantly associated with a reduced risk of AF while intermediate PA was not (0.68 [0.47 - 0.98] and 1.00 [0.78-1.29], respectively). In participants with baseline CVD, ideal PA or intermediate PA was not associated with incident AF. Conclusion: Ideal PA was associated with a reduced risk of AF in participants without baseline CVD in this AA community cohort. Our findings show intertwined relationship among PA, CVD, and incident AF. Physical activity could be a possible therapeutic target to reduce AF incidence in the AA general population without CVD.