Background: Female sex is considered a risk factor for thromboembolism in patients with atrial fibrillation (AF), and is included in the risk stratification scheme, CHA2DS2-VASc score. The purpose of the present study was to investigate the clinical outcomes of female Japanese AF patients.Methods and Results:The Fushimi AF Registry is a community-based prospective survey of the AF patients in Fushimi-ku, Kyoto. Follow-up data were available for 3,878 patients. Female AF patients (n=1,551, 40.0%) were older (77.0 vs. 71.4 years; P<0.001) than male patients (n=2,327, 60.0%). Female patients were more likely to have heart failure (31.1% vs. 23.7%; P<0.001). Previous stroke incidence (19.2% vs. 21.4%; P=0.083) was comparable between male and female patients. During the median follow-up period of 1,102 days, Cox regression analysis demonstrated that female sex was not independently associated with a risk of stroke or systemic embolism (adjusted hazard ratio [HR] 0.74; 95% confidence interval [CI]: 0.54-1.00, P=0.051). However, female sex showed an association with a lower risk of intracranial hemorrhage (adjusted HR 0.54; 95% CI: 0.30-0.95, P=0.032) and all-cause death (adjusted HR 0.56; 95% CI: 0.46-0.68, P<0.001).
Conclusions: We demonstrated that female sex is not independently associated with an increased risk of thromboembolism, but is associated with a decreased risk of intracranial hemorrhage and all-cause death in Japanese AF patients enrolled in the Fushimi AF Registry.
Keywords: Atrial fibrillation; Intracranial hemorrhage; Sex differences; Stroke.