title: Low-dose aspirin for prevention of stroke in low-risk patients with atrial fibrillation: Japan Atrial Fibrillation Stroke Trial.
abstract: OBJECTIVE
  Although the efficacy of anticoagulant therapy for primary prevention of stroke in patients with nonvalvular atrial fibrillation (NVAF) has been established, efficacy of antiplatelet therapy for low-risk patients is disputable in Japanese patients because of the frequent hemorrhagic complications. We examined the efficacy and safety of aspirin therapy in Japanese patients with NVAF in a prospective randomized multicenter trial.
  
  
  METHODS
  Patients with NVAF were randomized to an aspirin group (aspirin at 150 to 200 mg per day) or a control group without antiplatelet or anticoagulant therapy. Primary end points included cardiovascular death, symptomatic brain infarction, or transient ischemic attack.
  
  
  RESULTS
  A total of 426 patients were randomized to aspirin group and 445 to no treatment. The trial was stopped earlier because there were 27 primary end point events (3.1% per year; 95% CI, 2.1% to 4.6% per year) in the aspirin group versus 23 (2.4% per year; 95% CI, 1.5% to 3.5% per year) in the control group, suggesting a low possibility of superiority of the aspirin treatment for prevention of the primary end point. In addition, treatment with aspirin caused a marginally increased risk of major bleeding (7 patients; 1.6%) compared with the control group (2 patients; 0.4%; Fisher exact test P=0.101).
  
  
  CONCLUSIONS
  For prevention of stroke in patients with NVAF, aspirin at 150 to 200 mg per day does not seem to be either effective or safe. Further prospective studies are needed to determine the best preventive therapy for cerebrovascular events in Japanese patients with NVAF.
authors.affiliation: Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, Suita, Japan. satoz@medone.med.osaka-u.ac.jp
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sato
authors.forename: Kinji
authors.initials: K
authors.lastname: Ishikawa
authors.forename: Akira
authors.initials: A
authors.lastname: Kitabatake
authors.forename: Satoshi
authors.initials: S
authors.lastname: Ogawa
authors.forename: Yukio
authors.initials: Y
authors.lastname: Maruyama
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Yokota
authors.forename: Takaya
authors.initials: T
authors.lastname: Fukuyama
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Doi
authors.forename: Seibu
authors.initials: S
authors.lastname: Mochizuki
authors.forename: Tohru
authors.initials: T
authors.lastname: Izumi
authors.forename: Noboru
authors.initials: N
authors.lastname: Takekoshi
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Yoshida
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Hiramori
authors.forename: Hideki
authors.initials: H
authors.lastname: Origasa
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Uchiyama
authors.forename: Masayasu
authors.initials: M
authors.lastname: Matsumoto
authors.forename: Takenori
authors.initials: T
authors.lastname: Yamaguchi
authors.forename: Masatsugu
authors.initials: M
authors.lastname: Hori
mesh_terms: D000368:Aged; D000925:Anticoagulants / Q000627:therapeutic use*; D001241:Aspirin / Q000627:therapeutic use*; D001281:Atrial Fibrillation / Q000628:therapy*; D002561:Cerebrovascular Disorders / Q000628:therapy; D005260:Female; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D015999:Multivariate Analysis; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use*; D011446:Prospective Studies; D012307:Risk Factors; D020521:Stroke / Q000517:prevention & control*; D013927:Thrombosis / Q000628:therapy; D016896:Treatment Outcome
chemical_list: D000925:Anticoagulants; D010975:Platelet Aggregation Inhibitors; D001241:Aspirin