Stroke is one of the most devastating complications in patients who have atrial fibrillation (AF).  High risk AF patients with a CHADS₂ score of 2 or higher require therapeutic anticoagulation.  The CHA₂DS₂-VASc scoring system helps in identifying high risk patients in those that have borderline risk.  Warfarin, maintaining a therapeutic INR of 2.0-3.0, is effective in reducing stroke risk by 65%.  However, warfarin has many limitations including the many dietary and drug interactions and the need for blood monitoring.  New anticoagulants, such as the direct oral thrombin inhibitor, dabigatran, and factor Xa inhibitors, rivaroxaban and apixaban, have been shown to reduce stroke at least as effectively as warfarin.