This book aims to:- Give a brief presentation on evidence-based medicine;- Describe the importance of using and adapting the Clinical Practice Guides (CPG's);- Make a brief summary about Atrial Fibrillation;- Describe the method used to select and analyze the quality of Practice Guides (GPC's) focused on the treatment of Atrial Fibrillation published between April 2014 and April 2019;- Present and discuss a matrix on the main pharmacological recommendations, with emphasis on:-- Importance of thromboembolic risk stratification (by CHA2DS2-VASc score) and bleeding risk stratification (by HAS-BLED score);-- Indication of anticoagulation based on stroke risk stratification;-- Comparison of safety and efficacy between warfarin and direct-acting anticoagulants;-- Importance of the approach to the elderly population by the Clinical Practice Guidelines (CPGs);-- Best way to adjust oral anticoagulation in special populations; and-- Main drug interactions and adverse events of oral anticoagulants.