Background: Oral anticoagulation (OAC) reduces ischemic stroke and death in high-risk patients with atrial fibrillation and flutter (AFF), but recent US emergency department (ED) patterns of OAC initiation on home discharge are poorly understood. We describe appropriate stroke prophylaxis action (including OAC initiation or anticoagulation clinic [ACC]) referral for OAC initiation) on ED discharge of high-risk AFF patients in a large integrated healthcare delivery system.
Methods: We examined adults with a primary incident diagnosis of nonvalvular AFF, high stroke risk (CHA2DS2-VASc score ≥ 2), no recent (<90d) OAC, who were eligible for thromboprophylaxis on discharge to home from 21 community EDs between 2010-2017. We extracted from electronic records the annual proportion of patients with appropriate stroke-prevention action. We also used multivariable Poisson regression to identify independent correlates of appropriate stroke prophylaxis action (gender, age, race, ethnicity, and stroke risk scores). We report results as adjusted relative risk ratios with 95% confidence intervals (aRR, CI).
Results: 3.4% were women, and median CHA2DS2-VASc score was 3 (IQR 2-4). Overall, most patients (87.0%) did not receive an OAC prescription or an ACC referral. Dabigatran was placed on the formulary in 2014, and by 2017, it surpassed warfarin: 9.5% of eligible patients were prescribed dabigatran and 6.7% were prescribed warfarin. ACC referrals were uncommon throughout (1.2%). From 2010-2017, appropriate action increased from 10.7 to 16.9%. Using Poisson regression, women were 16% less likely to receive appropriate action compared to men, holding age, race, ethnicity, and stroke risk scores equal (aRR 0.84, CI 0.70-0.99)
Conclusion: Within a large, community-based AFF population considered at increased stroke risk, prescription of OAC at ED discharge increased with the availability of dabigatran. Few patients, however, were referred to the ACC and women were less likely to receive appropriate stroke-prophylaxis action compared to men. Many opportunities exist to improve the proportion of high-risk AFF patients leaving the ED with a plan for stroke prevention, including addressing gender disparities and leveraging available ACC.