The CHA2DS2-VASc score and the risk of ischemic stroke in community-dwelling individuals with and without atrial fibrillation: The Atherosclerosis Risk In Communities (ARIC) study

Abstract

Abstract type Clinical Research. Presentation type Oral Presentation. Introduction Recent evidence from hospital-based cohorts suggests that the CHA2DS2-VASc score may be used to predict ischemic stroke in individuals without atrial fibrillation (AF). We aimed to evaluate the association of the CHA2DS2-VASc score for incident ischemic stroke, with and without AF, among community-dwelling individuals. Methodology We included all participants from the Atherosclerosis Risk in Communities (ARIC) study who attended visit 4 (1996–98) and had no prior AF, stroke, and were not on warfarin. Incident AF was ascertained from study ECGs and hospital discharge diagnosis codes, and stroke was physician-adjudicated. AF cases were matched with non-AF controls based on CHA2DS2-VASc variables, and participants were censored if they began anticoagulants during the follow-up period. Time-to-event and competing risk analyses were used to calculate the incidence rates of ischemic stroke by CHA2DS2-VASc score, stratified by AF status. RESULTS This analysis included 4,039 participants (mean age, 74.6 ± 6.8 years; 50% women; 14% blacks) of whom 1,180 had incident AF. After a mean follow-up of 5.1 ± 4.2 years, 182 (4.5%) developed ischemic stroke. Higher CHA2DS2-VASc score was associated with higher incidence of ischemic stroke in participants with and without AF. In participants without AF, the absolute 1-year risk remained low (0.6%) even in those with CHA2DS2-VASc score of ⩾6. In participants with AF, the absolute 1-year risk of ischemic stroke was 3.2% even in those with CHA2DS2-VASc score of 0–1) Conclusion The risk of ischemic stroke is low across CHA2DS2-VASc score categories in community-dwelling individuals without AF. Individuals with AF are at high risk for ischemic stroke even with low CHA2DS2-VASc score, suggesting the need for stroke prevention in individuals with AF and one CHA2DS2-VASc stroke risk factor.