See article vol. 28: 241-248 Atrial fibrillation (AF) has been recognized as an intervenable risk factor for incident cardioembolic stroke in various studies. Today, patients with AF receive oral anticoagulation therapy to prevent future thromboembolic events, based on clinical risk scores such as the CHADS2 and CHA2DS2-VASc. Both scores incorporate risk factors such as age, sex, hypertension, diabetes mellitus, congestive heart failure, previous stroke, and other vascular diseases that incrementally increase the likelihood of incident stroke events, particularly among the Caucasian population. Similarly, in a joint cohort of five representative AF registries in Japan, previous stroke, advanced age, hypertension, low body mass index, and persistent/permanent AF were identified as independent risk factors for ischemic stroke.