Factor Xa Inhibitors Versus Vitamin K Antagonists for Preventing Cerebral or Systemic Embolism in Patients With Atrial Fibrillation

Atrial fibrillation (AF) is the most common type of arrhythmia in adults and becomes more common with increased age. Management of people with AF aims at preventing thromboembolic complications, and anticoagulant treatment with vitamin K antagonists (VKAs) has been the therapy of choice for many decades. A new class of anticoagulants, the factor Xa inhibitors, seems to have several pharmacological and practical advantages over VKAs, and some have recently been approved by regulatory authorities in the United States and Europe for stroke prevention in people with AF.The objectives of this study were to assess the effectiveness and safety of treatment with factor Xa inhibitors versus VKAs for the prevention of cerebral or systemic embolic events in people with nonvalvular AF.We searched the trial registers of the Cochrane Stroke Group, the Cochrane Central Register of Controlled Trials, MEDLINE, and EMBASE (all to June 2013). We also screened reference lists and contacted pharmaceutical companies, authors, and sponsors of relevant published trials.We identified randomized, controlled trials that directly compared the effects of long-term treatment (>4 weeks) with factor Xa inhibitors and VKAs for the prevention of cerebral and systemic embolism in patients with AF. We included patients with and without a previous stroke or transient ischemic attack.The primary end point was the composite end point of all strokes and systemic embolic events. Two authors independently extracted data and assessed trial quality …