Predictors of Cardioembolic Stroke in Japanese Patients with Atrial Fibrillation in the Fushimi AF Registry

Background: Large-scale clinical trials have analyzed risk factors for any ischemic stroke in patients with atrial fibrillation (AF). However, the risk factors for cardioembolic stroke (CES), specifically, have not been reported. To clarify the risk factors for CES and clinically significant cardioembolic infarction, we examined the incidence of CES and larger infarct volume (IV) (> 30 mL) CES, employing the Fushimi AF Registry, a community-based prospective cohort of AF patients in the Fushimi ward, Kyoto, Japan. Methods: A total of 4,182 Fushimi AF patients were enrolled from March 2011 to December 2014. The risk factors for CES were evaluated using multivariate analysis. Results: Of 4,182 patients enrolled, 3,749 patients were observed for ≥1 year. During the follow-up period (mean duration, 979 ± 7.7 days), 91/3,749 patients experienced a CES (2.43%). Significant risk factors associated with CES were older age (odds ratio [OR], 1.31; 95% confidence interval [CI], 1.01–1.72; p = 0.046), low body weight (OR, 1.30; 95% CI, 1.03–1.65; p = 0.033), sustained AF (OR, 1.67; 95% CI, 1.05–2.71; p = 0.034), and previous stroke or transient ischemic attack (TIA) (OR, 1.94; 95% CI, 1.22–3.06; p = 0.004). Predictors of a large IV were chronic kidney disease (CKD) (OR, 2.08; 95% CI, 1.09–4.05; p = 0.027) and previous stroke/TIA (OR, 2.27; 95% CI, 1.19–4.24; p = 0.011). Conclusions: In this population-based cohort of Japanese patients with AF, in addition to previous stroke/TIA and older age, sustained AF and low body weight emerged as risk factors for CES, as opposed to any stroke, which may have a different risk profile. Patients with CKD or previous stroke/TIA who developed cardioembolic infarction exhibited more advanced severity. There is a need for direct oral anticoagulants that can be used safely in patients with comorbid AF and CKD.