Abstract P114: Association of Atrial Fibrillation With Incidence of Extracranial Systemic Embolic Events (SEE) in the Atherosclerosis Risk in Communities (ARIC) Study

Abstract

Objectives: Embolic stroke is a major complication of atrial fibrillation (AF). Mechanisms that lead to elevated stroke risk in AF are also likely to increase risk of extracranial systemic embolic events (SEE). However, little is known about the magnitude of the association of AF with SEE, needed to fully characterize the impact of AF on cardiovascular outcomes. We evaluated the association of AF with SEE and the prediction of SEE among persons with AF in a community-based cohort. Methods: We included 14,941 participants of the ARIC study (mean age, 54 ± 6, 55% women, 74% white) without AF at baseline (1987-89) and followed through 2017. AF was identified from study electrocardiograms, hospital discharges, and death certificates. SEE was defined as the presence of hospitalization discharge codes ICD-9-CM 444.xx or ICD-10-CM I74.x (Arterial embolism and thrombosis) in any position. CHA2DS2-VASc score, a predictor of stroke risk in AF, was calculated at the time of AF diagnosis. Cox models adjusting for fixed and time-varying covariates were used to estimate associations of incident AF with SEE risk and between CHA2DS2-VASc score and SEE risk in those with incident AF. Results: Among eligible participants, 3,114 developed AF and 270 had a SEE event. Incident AF was associated with increased risk of SEE [hazard ratio (HR) = 3.6, 95% confidence interval (CI) 2.6 - 5.0], after adjusting for baseline and time-dependent covariates (Table). The association of incident AF with SEE was stronger in women (HR 5.3, 95% CI 3.3 - 8.4) than in men (HR 2.7, 95% CI 1.7 - 4.3) (p for interaction = 0.002). In participants with incident AF, we identified 59 SEE events. Higher CHA 2 DS 2 -VASc score was associated with increased SEE risk (HR per 1-point increase = 1.2, 95% CI 1.1 - 1.5). Conclusions: AF is associated with more than a tripling of the risk of SEE, with a stronger association in women than in men. CHA 2 DS 2 -VASc is associated with SEE risk in AF patients, highlighting the value of the score to predict outcomes and guide treatments in persons with AF.