title: An update on antithrombotic therapy in atrial fibrillation: the role of newer and emergent drugs.
abstract: Atrial fibrillation (AF) is the most common cardiac arrhythmia and is associated with         potentially dreadful cardioembolic complications such as stroke. The risk of stroke is         stratified based on the patient's comorbid conditions using several scoring systems.         Patients are treated with oral anticoagulation using warfarin or aspirin based on their         cardioembolic stroke risk. Although warfarin has been the only effective therapy, it         is underutilized clinically due to concern for multiple drug-to-drug and drug-to-food         interactions and hemorrhagic complications. Dual antiplatelet therapy with aspirin and         clopidogrel has been studied as a potential alternative anticoagulant for AF patients;         however, the combination of aspirin and clopidogrel was noted to be inferior to         warfarin in preventing strokes, with an increased risk of bleeding. As a result, newer         anticoagulant agents, including direct thrombin inhibitors, direct and indirect factor         Xa inhibitors, and vitamin K antagonists, have been developed and evaluated in AF         patients. Results from a recent study demonstrated that high-dose dabigatran, a direct         thrombin inhibitor, was superior to warfarin in preventing stroke and systemic embolism         with similar bleeding risk. It ultimately received approval by the US Food and Drug         Administration for stroke prophylaxis for nonvalvular AF patients. There are several         other direct factor Xa inhibitors currently under study. Dabigatran may be considered         in AF patients who are intolerant to warfarin or unwilling or unable to follow-up with         frequent laboratory monitoring. Other newer anticoagulant agents also provide us with         possible suitable alternatives to warfarin, and their clinical use will depend on the results         from ongoing studies.
authors.affiliation: Division of Cardiology, Veterans Administration Central California Healthcare System/University of California, San Francisco, Fresno, CA, USA.
authors.forename: Prakash
authors.initials: P
authors.lastname: Deedwania
authors.forename: Grace W
authors.initials: GW
authors.lastname: Huang
mesh_terms: D000284:Administration, Oral; D000925:Anticoagulants / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D000991:Antithrombins / Q000627:therapeutic use; D001281:Atrial Fibrillation / Q000097:blood / Q000150:complications / Q000188:drug therapy*; D001777:Blood Coagulation / Q000187:drug effects*; D004347:Drug Interactions; D004617:Embolism / Q000097:blood / Q000209:etiology / Q000517:prevention & control*; D065427:Factor Xa Inhibitors; D005343:Fibrinolytic Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D006470:Hemorrhage / Q000139:chemically induced; D006801:Humans; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D011314:Preventive Health Services; D018570:Risk Assessment; D012307:Risk Factors; D020521:Stroke / Q000097:blood / Q000209:etiology / Q000517:prevention & control*; D016896:Treatment Outcome
chemical_list: D000925:Anticoagulants; D000991:Antithrombins; D065427:Factor Xa Inhibitors; D005343:Fibrinolytic Agents; D010975:Platelet Aggregation Inhibitors