Association of atrial fibrillation without cardiovascular comorbidities and stroke risk: From the regards study

• Authors: Matthew J. Singleton, Wake Forest University; Muhammad Imtiaz-Ahmad, Hospital Medicine Wake; Hooman Kamel, Weill Cornell Medical College; Wesley O neal, Emory University; Suzanne E. Judd, The University of Alabama at Birmingham; Virginia J. Howard, The University of Alabama at Birmingham; George Howard, The University of Alabama at Birmingham; Elsayed Z. Soliman, Wake Forest University; Prashant D. Bhave, Wake Forest University
• Journal Title: Journal of the American Heart Association
• Volume: Volume 9, Number 12
• Publisher: American Heart Association | 2020-06-16, Pages e016380-e016380
• Type of Work: Article | Final Publisher PDF
• Publisher DOI: http://doi.org/10.1161/JAHA.120.016380
• Subjects: Health Sciences, Medicine and Surgery; Health Sciences, Epidemiology; Biology, Biostatistics; Biology, Neuroscience
• Keywords: arrhythmia; atrial fibrillation; comorbidities; risk; stroke; Aged; Atrial Fibrillation; Comorbidity; Embolic Stroke; Female; Humans; Incidence; Ischemic Stroke; Longitudinal Studies; Male; Middle Aged; Prognosis; Risk Assessment; Risk Factors; Time Factors; United States

Abstract

Background Atrial fibrillation (AF) is associated with a 5‐fold increased stroke risk. While most patients with AF warrant anticoagulation, optimal treatment remains uncertain for patients with AF without cardiovascular comorbidities because the risk of stroke in this population has not been well‐characterized. Methods and Results Participants (N=28 253; 55% women, mean age 64.6±9.4 years), from the REGARDS (Reasons for Geographic and Racial Differences in Stroke) study (2003–present) were classified into 1 of 4 groups based on the presence or absence of AF and the presence or absence of cardiovascular comorbidities. Cox proportional hazards analysis was used to compare the risk of stroke between groups. During 244 560 person‐years of follow‐up (median 8.7 years), 1206 strokes occurred. Compared with patients with neither AF nor cardiovascular comorbidities, we did not find an increased stroke risk (hazard ratio [HR], 1.23; 95% CI, 0.62–2.18 [P=0.511]) among participants with AF alone. Participants without AF but with cardiovascular comorbidities had both an elevated stroke risk (HR, 1.77; 95% CI, 1.48–2.18 [P<0.0001]) and an increased risk of cardioembolic stroke (HR, 2.34; 95% CI, 1.48–3.90 [P=0.0002]). Conclusions In this large cohort of participants with AF without cardiovascular comorbidities, we found that AF itself, without cardiovascular comorbidities, did not confer increased risk of stroke. Cardiovascular comorbidities, however, were associated with an increased risk of both stroke of any type and cardioembolic stroke, even in the absence of AF.