Atrial Fibrillation and Stroke Symptoms in the REGARDS Study

Background It is unknown if stroke symptoms in the absence of a stroke diagnosis are a sign of subtle cardioembolic phenomena. The objective of this study was to examine associations between atrial fibrillation (AF) and stroke symptoms among adults with no clinical history of stroke or transient ischemic attack (TIA). Methods and Results We evaluated associations between AF and self-reported stroke symptoms in the national, prospective REGARDS (Reasons for Geographic and Racial Differences in Stroke) cohort. We conducted cross-sectional (n=27 135) and longitudinal (n=21 932) analyses over 8 years of follow-up of REGARDS participants without stroke/transient ischemic attack and stratified by anticoagulant or antiplatelet agent use. The mean age was 64.4 (SD +/- 9.4) years, 55.3% were women, and 40.8% were Black participants; 28.6% of participants with AF reported stroke symptoms. In the cross-sectional analysis, comparing participants with and without AF, the risk of stroke symptoms was elevated for adults with AF taking neither anticoagulants nor antiplatelet agents (odds ratio [OR], 2.22; 95% CI, 1.89-2.59) or antiplatelet agents only (OR, 1.92; 95% CI, 1.61-2.29) but not for adults with AF taking anticoagulants (OR, 1.08; 95% CI, 0.71-1.65). In the longitudinal analysis, the risk of stroke symptoms was also elevated for adults with AF taking neither anticoagulants nor antiplatelet agents (hazard ratio [HR], 1.41; 95% CI, 1.21-1.66) or antiplatelet agents only (HR, 1.23; 95% CI, 1.04-1.46) but not for adults with AF taking anticoagulants (HR, 0.86; 95% CI, 0.62-1.18). Conclusions Stroke symptoms in the absence of a stroke diagnosis may represent subclinical cardioembolic phenomena or "whispering strokes." Future studies examining the benefit of stroke symptom screening may be warranted.