When the NOAC trials are considered as a group, the direct thrombin inhibitor and factor Xa inhibitors were at least noninferior and, in some trials, superior to warfarin for preventing stroke and systemic embolism and were associated with lower risks of serious bleeding. I A Among patients treated with warfarin, the international normalized ratio (INR) should be determined at least weekly during initiation of anticoagulant therapy and at least monthly when anticoagulation (INR in range) is stable.S4.1.1-12 S4.1.1-14 MODIFIED: Antithrombotic was changed to anticoagulant. I B In patients with AF (except with moderate- to-severe mitral stenosis or a mechanical heart valve), the CHA2 -VASc score is recommended for assessment of stroke MODIFIED: Exclusion criteria are now defined as moderate-to-severe mitral stenosis or a mechanical heart valve. Patients with AF with bioprosthetic heart valves are addressed in the supportive text. (Section 4.1. in the 2014 AF guideline) I B For patients with AF who have mechanical heart valves, warfarin is MODIFIED: New information is included in the supportive text. CLINICAL STATEMENTS AND GUIDELINES I B Selection of anticoagulant therapy should be based on the risk of thromboembolism, irrespective of whether the AF pattern is paroxysmal, persistent, or MODIFIED: Antithrombotic was changed to anticoagulant. I B-NR Renal function and hepatic function should be evaluated before initiation of a NOAC and should be reevaluated at least MODIFIED: Evaluation of hepatic function was added. LOE was updated from B to B-NR. New evidence was added. (Section 4.1. in the 2014 AF Guideline) I C In patients with AF, anticoagulant therapy should be individualized on the basis of shared decision-making after discussion of the absolute risks and relative risks of stroke and bleeding, as well as the patient s values and preferences. MODIFIED: Antithrombotic was changed to anticoagulant. 