IS THE GENDER SPECIFIC RISK OF ISCHEMIC STROKE IN ATRIAL FIBRILLATION RELATED TO DIFFERENCES IN ANTICOAGULATION?

Abstract

Abstract Category: 26. Clinical Electrophysiology—Supraventricular Arrhythmias Authors: Renee Sullivan, Jingyang Zhang, Gideon Zamba, Gregory YH Lip, Brian Olshansky, University of Iowa Hospitals and Clinics, Iowa City, IA, University of Birmingham, Birmingham, United KingdomBackground: Compared to men, women with atrial ibrillation (AF) are at higher risk of stroke but the reason for this is uncertain. We postulated that gender-related differences in risk of ischemic stroke are related to the time in the therapeutic range (TTR) (i.e., INR of 2-3).Methods: From the AFFIRM database of 4060 patients with AF, we determined the incidence of ischemic stroke by gender for those who were taking warfarin. We evaluated the INR at the time of ischemic stroke for women and men and calculated the TTR by the Rosendaal method. We determined the relationship between gender and ischemic stroke by TTR.Results: Compared to men, women had more ischemic strokes (5% vs 3%, p=0.002). The mean INR near the time of ischemic stroke was 2 for women and men but median values were subtherapeutic (1.7 and 1.8, respectively). Women spent more time outside the therapeutic range than men (p=0.0001) and had INR values more commonly below the therapeutic range (p=0.0002). A higher TTR was associated with lower risk of ischemic stroke for women but not men. Women with comparably high TTR (≥66%) still had more ischemic strokes than men (p=0.009).Conclusions: In AFFIRM, compared to men, women had more ischemic strokes and spent a greater percent of time outside, and generally below, the therapeutic range. This higher incidence of stroke may partly be due to differences in TTR. To reduce risk of stroke, women with AF may beneit from novel anticoagulants or require more aggressive anticoagulation compared to men.Gender N % Outside TTR * % Below TTR **Men 2337 37+/-0.5 26+/-0.5Women 1499 40+/-0.7 29+/-0.7* p=0.0001 **p=0.0002