Clinical trials update: recent and ongoing studies in anticoagulation for atrial fibrillation

Atrial fibrillation is the most common sustained cardiac arrhythmia in the adult population, with a marked increased risk associated with age. Perhaps the most devastating complications of atrial fibrillation include acute ischemic stroke or systemic embolization. Vitamin K antagonists such as warfarin have served as the primary pharmacologic agent for the prevention of these thrombotic complications. Despite the widespread use of vitamin K antagonists, their effectiveness is hindered by several factors, including delayed onset of action, multiple food and drug interactions, onerous monitoring and dosing regimens, and a narrow therapeutic window. To address these limitations, multiple novel oral anticoagulants targeting thrombin or factor Xa have progressed through clinical development or received regulatory approval for clinical use in recent years. These agents offer the potential for enhanced efficacy, as well as an improved safety profile. Here, the phase II and III clinical trial data detailing the potential risks and benefits of these agents are reviewed.