New recommendation Atrial fibrillation For patients with valvular atrial fibrillation at high risk for stroke, defined as a CHA2 - VASc score of 2, and acceptably low risk for hemorrhagic complications, chronic oral anticoagulant therapy with warfarin at a target INR of 2.0 to 3.0 is recommended (Class I; Level of Evidence A). New recommendation For patients with nonvalvular atrial fibrillation, a CHA2 -VASc score of 2, and acceptably low risk for hemorrhagic complications, oral anticoagulants are recommended (Class I). Options include warfarin (INR, 2.0 to 3.0) (Level of Evidence A), dabigatran (Level of Evidence B), apixaban (Level of Evidence B), and rivaroxaban (Level of Evidence B). The selection of antithrombotic agent should be individualized on the basis of patient risk factors (particularly risk for intracranial hemorrhage), cost, tolerability, patient preference, potential for drug interactions, and other clinical characteristics, including time INR is in therapeutic range for patients taking warfarin. New recommendation For patients with nonvalvular atrial fibrillation and CHA2 -VASc score of 0, it is reasonable to omit antithrombotic therapy (Class IIa; Level of Evidence B). New recommendation For patients with nonvalvular atrial fibrillation, a CHA2 -VASc score of 1, and acceptably low risk for hemorrhagic complication, no antithrombotic therapy, anticoagulant therapy, or aspirin therapy may be considered (Class IIb; Level of Evidence C). The selection of antithrombotic agent should be individualized on the basis of patient risk factors (particularly risk for intracranial hemorrhage), cost, tolerability, patient preference, potential for drug interactions, and other clinical characteristics, including time INR is in therapeutic range for patients taking warfarin. 