Sex Differences in the Management of Oral Anticoagulation and Outcomes for Emergency Department Presentation of Incident Atrial Fibrillation

Study objective: To examine sex differences in oral anticoagulation management and outcomes among patients with incident nonvalvular atrial fibrillation presenting to the emergency department (ED). Methods: We identified patients older than 20 years presenting to the ED with incident nonvalvular atrial fibrillation between April 1, 2012, and March 30, 2019, using linked administrative databases in Alberta, Canada. We assessed the use of and adherence to oral anticoagulants at 1 year using the proportion of days covered for direct oral anticoagulants and time in therapeutic range for warfarin. Outcomes included stroke, heart failure, and all-cause mortality at 1 year. Results: Of the 28,886 patients with nonvalvular atrial fibrillation presenting to ED, 44% were females. After adjustment, the rate of oral anticoagulant use was 5% lower in females with a guideline indication than that in males (adjusted hazard ratio 0.95, 95% confidence interval [CI] 0.91 to 0.99) discharged home, and there was no difference among admitted patients (adjusted hazard ratio 1.00, 95% CI 0.96 to 1.05). Females had high adherence to direct oral anticoagulants (>= 80% proportion of days covered) compared to males (discharged: 77.7% versus 74.0%; admitted: 80.0% versus 76.7%; adjusted odds ratio for females: 1.15, 95% CI 1.02 to 1.29). More than half of the females and males had poor warfarin control (time in therapeutic range <65%) regardless of discharge status. In multivariable analyses, there was no sex difference in outcomes except a 1.48-fold (95% CI 1.14 to 1.92) higher risk of stroke in females. Conclusion: Females with incident nonvalvular atrial fibrillation discharged from the ED are less likely to receive oral anticoagulants than males. When oral anticoagulant treatment is initiated, females have high adherence to direct oral anticoagulants, and both the sexes have poor warfarin control. At 1 year, females were at a significantly higher risk of developing stroke. Copyright (C) 2022 by the American College of Emergency Physicians.