Abstract P105: Women with Atrial Fibrillation have Increased Risk of Incident Stroke: Insights from a Propensity-Matched Study of the AFFIRM Trial

Abstract

Background: Women with atrial fibrillation (AF) have been reported to have poor outcomes. It remains unclear if this association is intrinsic or mediated by the higher comorbidity burden of female AF patients. Therefore, we examined the association between sex and outcomes in a balanced cohort of propensity-matched AF patients who participated in the Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) trial. Methods: Of the 4060 AFFIRM patients, 1594 (39%) were women. Propensity scores for female sex were calculated for each of the 4060 patients, and were used to assemble a cohort of 1097 pairs of men and women who were balanced on 51 baseline characteristics, including major cardiovascular (CV) risk factors and medication use, including warfarin. Matched Cox regression models were used to estimate the association between female sex and outcomes during 6 years of follow-up. Results: Patients (n=4060) had a mean (±SD) age of 70 (±8) years and 13% were African American. All-cause mortality occurred in 19% and 15% of matched men and women, respectively (matched HR when women were compared to men, 0.88; 95% CI, 0.69-1.11; p=0.279). All-cause hospitalization occurred in 61% of both men and women (matched HR for women, 1.06; 95% CI, 0.93-1.21; p=0.372). Sex was not associated with CV hospitalization (matched HR for women, 1.13; 95% CI, 0.97-1.32; p=0.111). Ischemic stroke occurred in 3% and 5% of matched men and women, respectively (OR when women were compared to men, 2.02; 95% CI, 1.28-3.18; p=0.002). There was no sex-related difference in major bleeding (7% each). Conclusion: In a cohort of AF patient in which men and women were well-balanced on 51 baseline characteristics including warfarin use, women had increased risk of stroke, but there was no sex-related variation in all-cause mortality or CV hospitalization.