Reviewers abbreviated RWI information is published in this document (Ap- pendix 2), and their detailed disclosures are available online. This document was approved for publication by the governing bodies of the ACC, AHA, and HRS and was endorsed by the Society of Thoracic Surgeons. Abbreviation Meaning/Phrase ACS acute coronary syndrome AF atrial fibrillation AHRE atrial high-rate episodes congestive heart failure, hypertension, age >75 years, diabetes mellitus, stroke/transient ischemia attack/ thromboembolism -VASc congestive heart failure, hypertension, age 75 years (doubled), diabetes mellitus, prior stroke or transient ischemic attack or thromboembolism (doubled), vascular disease, age 65 to 74 years, sex category CI confidence interval CKD chronic kidney disease CMS US Centers for Medicare & Medicaid Services CrCl creatinine clearance DAPT dual-antiplatelet therapy FDA US Food and Drug Administration HF heart failure HFrEF heart failure with reduced left ventricular ejection fraction HR hazard ratio INR international normalized ratio LAA left atrial appendage LV left ventricular MI myocardial infarction NOAC non vitamin K oral anticoagulant PCI percutaneous coronary intervention RCT randomized controlled trial TIMI Thrombolysis in Myocardial Infarction CLINICAL STATEMENTS AND GUIDELINES 4. PREVENTION OF THROMBOEMBOLISM 4.1. Risk-Based Anticoagulant Therapy (Modified From Section 4.1., Risk-Based Antithrombotic Therapy, in the 2014 AF Guideline) 4.1.1. Selecting an Anticoagulant Regimen Balancing Risks and Benefits (Modified From Section 4.1.1., Selecting an Antithrombotic Regimen Balancing Risks and Benefits, in the 2014 AF Guideline) Introductory Text The distinction between nonvalvular and valvular AF has confused clinicians, varying among AF clinical tri- als of non vitamin K oral anticoagulants (NOACs) (ie, dabigatran [a direct thrombin inhibitor] and rivaroxa- ban, apixaban, and edoxaban [factor Xa inhibitors]; also referred to as direct-acting oral anticoagulants [DOACs]) and between North American and Europe- an AF guidelines. 