title: Rivaroxaban versus warfarin in Japanese patients with nonvalvular atrial fibrillation in relation to the CHADS2 score: a subgroup analysis of the J-ROCKET AF trial.
abstract: BACKGROUND
  Results from a trial of rivaroxaban versus warfarin in 1280 Japanese patients with atrial fibrillation (J-ROCKET AF) revealed that rivaroxaban was noninferior to warfarin with respect to the principal safety outcome. In this subanalysis, we investigated the safety and efficacy of rivaroxaban and warfarin in relation to patients' CHADS2 scores.
  
  
  RESULTS
  The mean CHADS2 score was 3.25, and the most frequent scores were 3 and 4. No statistically significant interactions were observed between principal safety outcome event rates and CHADS2 scores with respect to treatment groups (P value for interaction = .700). Irrespective of stratification into moderate- and high-risk groups based on CHADS2 scores of 2 and 3 or more, respectively, no differences in principal safety outcome event rates were observed between rivaroxaban- and warfarin-treated patients (moderate-risk group: hazard ratio [HR], 1.06; 95% confidence interval [CI], .58-1.95; high-risk group: HR, 1.11; 95% CI, .86-1.45; P value for interaction = .488). The primary efficacy end point rate in the rivaroxaban-treated group was numerically lower than in the warfarin-treated group, regardless of risk group stratification (moderate-risk group: HR, .46; 95% CI, .09-2.37; high-risk group: HR, .49; 95% CI, .22-1.11; P value for interaction = .935).
  
  
  CONCLUSIONS
  This subanalysis indicated that the safety and efficacy of rivaroxaban compared with warfarin were similar, regardless of CHADS2 score.
authors: Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka, Japan.
authors: Masatsugu
authors: M
authors: Hori
authors: Department of Clinical Neuroscience and Therapeutics, Hiroshima University, Hiroshima, Japan.
authors: Masayasu
authors: M
authors: Matsumoto
authors: Department of Neurology, Saitama Medical University International Medical Center, Saitama, Japan.
authors: Norio
authors: N
authors: Tanahashi
authors: Division of Cardiovascular Medicine, Saitama Medical Center, Jichi Medical University, Saitama, Japan.
authors: Shin-Ichi
authors: S
authors: Momomura
authors: Department of Neurology, Tokyo Women's Medical University, Tokyo, Japan.
authors: Shinichiro
authors: S
authors: Uchiyama
authors: Department of Medicine (Cardiology), Tokai University School of Medicine, Tokyo, Japan.
authors: Shinya
authors: S
authors: Goto
authors: Department of Cardioangiology, Kitasato University School of Medicine, Sagamihara City, Kanagawa, Japan.
authors: Tohru
authors: T
authors: Izumi
authors: Institute for Clinical Research, Osaka National Hospital, Osaka, Japan.
authors: Yukihiro
authors: Y
authors: Koretsune
authors: Bayer Yakuhin Ltd, Osaka, Japan.
authors: Mariko
authors: M
authors: Kajikawa
authors: Bayer Yakuhin Ltd, Osaka, Japan.
authors: Masaharu
authors: M
authors: Kato
authors: Bayer Yakuhin Ltd, Osaka, Japan.
authors: Hitoshi
authors: H
authors: Ueda
authors: Bayer Yakuhin Ltd, Osaka, Japan. Electronic address: hori-ma@mc.pref.osaka.jp.
authors: Kazuma
authors: K
authors: Iekushi
authors: Bayer Yakuhin Ltd, Osaka, Japan.
authors: Satoshi
authors: S
authors: Yamanaka
authors: Bayer Yakuhin Ltd, Osaka, Japan.
authors: Masahiro
authors: M
authors: Tajiri
mesh_terms: D000368:Aged; D000925:Anticoagulants / Q000009:adverse effects / Q000627:therapeutic use*; D044466:Asian People; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000188:drug therapy* / Q000208:ethnology / Q000401:mortality; D018572:Disease-Free Survival; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D053208:Kaplan-Meier Estimate; D008297:Male; D009025:Morpholines / Q000009:adverse effects / Q000627:therapeutic use*; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D000069552:Rivaroxaban; D020521:Stroke / Q000175:diagnosis / Q000208:ethnology / Q000401:mortality / Q000517:prevention & control*; D013876:Thiophenes / Q000009:adverse effects / Q000627:therapeutic use*; D013997:Time Factors; D016896:Treatment Outcome; D014859:Warfarin / Q000009:adverse effects / Q000627:therapeutic use*
chemical_list: D000925:Anticoagulants; D009025:Morpholines; D013876:Thiophenes; D014859:Warfarin; D000069552:Rivaroxaban
keywords: Atrial fibrillation; CHADS(2) score; oral anticoagulation; stroke prevention