Direct Factor Xa Inhibitor YM150 for Prevention of Stroke in Subjects With Non-Valvular Atrial Fibrillation

Inclusion Criteria: Subjects are eligible for the study if all of the following apply: * Subject has paroxysmal permanent or persistent NVAF * Subject has INR of 2.0 or below and an aPTT ≤ 1.5 times the upper limit of normal at the baseline visit. * Legal minimum age requirement (country-specific). * Written informed consent has been obtained. Exclusion Criteria: * History of heart valve disorders * History of rheumatic fever. * History of stroke and/or systemic embolism (including TIA). * History of Acute Coronary Syndrome (ACS). * Indication for warfarin other than NVAF. * Known hemorrhagic disorder and/or coagulation disorder. * Active bleeding or any condition associated with increased risk of bleeding.