F10 and atrial fibrillation: There have been four randomized clinical trials comparing novel oral anticoagulants to warfarin in nonvalvular AF: RE-LY, Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared with Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation (ROCKET-AF), ARISTOTLE, and ENGAGE AF-TIMI 48.