Abstract 14594: Gender Differences in Use of Anti-Coagulant for Atrial Fibrillation: A Report from the NCDR®

Background: Women with atrial fibrillation (AF) have a higher risk of thromboembolism compared to men. In contemporary practice, whether rates of anticoagulation use according to thromboembolic risk vary by gender and if this relationship has changed over time with introduction of expanded treatment options (novel oral anticoagulants [NOACs]) are unknown. Methods: Using the outpatient National Cardiovascular Data Registry (NCDR) PINNACLE registry from 2010-2014, oral anticoagulation (OAC- warfarin or novel anticoagulant) use was compared in women and men with non-valvular AF and CHA2DS2-VASc scores ≥ 2. Patients with documented contraindications to anticoagulation were excluded. Multivariable logistic regression models assessed the association between gender and OAC use (at each CHA2DS2-VASc level) adjusted for demographic and clinical factors, and accounting for clustering by practice using generalized estimating equations. Temporal trends in OAC use were also compared. Results: Of the 658,341 patients with non-valvular AF and CHADS2VASc ≥2, 45.2% were women. The average CHADS2VASc score for women and men was similar (mean±SD, 3.4±1.16 vs 3.4 ±1.19, respectively, p = 0.245). At all thromboembolic risk levels women were less likely than men to have any anticoagulant prescribed (e.g. at CHA2DS2-VASc score = 4 53.4% of women vs. 56.1% of men received OAC), in adjusted analysis, RR 0.95, 95% CI 0.94-0.96, p <0.001(FIGURE). In temporal analysis, use of OAC increased over time in women and men (p < 0.001 for trend) with increased NOAC use in both genders (p <0.001 for trend). Conclusions: In this contemporary, ambulatory cohort of patients with non-valvular AF, women were slightly less likely to receive OAC across the spectrum of thromboembolic risk. Further studies are needed to understand the causes of these differences such as under-appreciation of gender as a risk factor or unequal treatment based on gender alone.