title: Antithrombotic therapy in atrial fibrillation.
abstract: OBJECTIVE
  To review the evidence for antithrombotic therapy in patients with nonrheumatic atrial fibrillation.
  
  
  METHODS
  Five primary prevention trials and one secondary prevention trial compare antithrombotic therapy with placebo or no treatment. Two trials also determine the efficacy and safety of acetylsalicylic acid.
  
  
  RESULTS
  Warfarin reduces the risk of stroke by 68%. The effect is consistent in all identifiable groups of patients with nonrheumatic atrial fibrillation, except patients at serious risk of hemorrhage. The absolute benefit of anticoagulants varies among patients because of markedly different inherent risk of stroke among patient subgroups.
  
  
  CONCLUSIONS
  Anticoagulant therapy should be considered for all patients with atrial fibrillation. Oral anticoagulant therapy is more effective than ASA in reducing the risk of stroke among patients with nonrheumatic atrial fibrillation.
authors: Faculty of Health Sciences, McMaster University, Hamilton, Ont.
authors: A G
authors: AG
authors: Turpie
authors: S J
authors: SJ
authors: Connolly
mesh_terms: D000925:Anticoagulants / Q000627:therapeutic use*; D001241:Aspirin / Q000627:therapeutic use*; D001281:Atrial Fibrillation / Q000150:complications / Q000188:drug therapy*; D002561:Cerebrovascular Disorders / Q000209:etiology / Q000517:prevention & control*; D006801:Humans; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use*; D011322:Primary Prevention; D012307:Risk Factors; D016896:Treatment Outcome; D014859:Warfarin / Q000627:therapeutic use*
chemical_list: D000925:Anticoagulants; D010975:Platelet Aggregation Inhibitors; D014859:Warfarin; D001241:Aspirin