title: Stroke prevention using dabigatran in elderly Chinese patients with atrial fibrillation.
abstract: BACKGROUND
  Little is known about the clinical benefit of a non-vitamin K antagonist oral anticoagulant compared with warfarin in elderly Chinese patients with atrial fibrillation (AF).
  
  
  OBJECTIVE
  The purpose of this study was to evaluate the clinical benefit of dabigatran in elderly (age ≥80 years) Chinese patients with nonvalvular AF with regard to the risk of ischemic stroke and intracranial hemorrhage (ICH).
  
  
  METHODS
  This was an observational study.
  
  
  RESULTS
  We studied 571 Chinese patients (mean age 84.8 ± 4.0 years; 58.1% women) with nonvalvular AF. The primary outcome was hospital admission for ischemic stroke, and the secondary outcome was admission for ICH. The mean CHA2DS2-VASc (congestive heart failure [1 point], hypertension [1 point], age 65-74 years [1 point] and age ≥75 years [2 points], diabetes mellitus [1 point], prior stroke or transient ischemic attack [2 points], vascular disease [1 point], sex category [female] [1 point]) and HAS-BLED (hypertension [1 point], abnormal renal/liver function [1 point], stroke [1 point], bleeding history [1 point] or predisposition [1 point], labile international normalized ratio [1 point], elderly [age >65 years] [1 point], drugs/alcohol concomitantly [1 point]) scores were 4.8 ± 1.6 and 2.4 ± 0.8, respectively. Of 571 patients, 129 (22.6%) were taking dabigatran 110 mg twice daily and the remaining were on warfarin. After a mean follow-up of 2.6 years (a total of 1471 patient-years), ischemic stroke occurred in 83 patients on warfarin (6.9% per year) compared with 4 patients on dabigatran (1.4% per year) (hazard ratio 0.22; 95% confidence interval 0.23-0.67). There were 8 incidences of ICH: 7 in patients on warfarin (0.59% per year) and 1 patient on dabigatran (0.35% per year). Dabigatran was associated with a substantially lower ischemic stroke risk (1.4% per year vs 5.4% per year) and similar ICH risk (0.35% per year vs 0.36% per year) as compared with warfarin with time in therapeutic range (TTR) ≥55%.
  
  
  CONCLUSIONS
  In elderly Chinese patients with AF, this study suggested that dabigatran achieved superior stroke risk reduction and similar risk of ICH compared with warfarin with TTR ≥55%. Dabigatran may be preferable to warfarin in elderly patients with AF for stroke prevention, particularly in those with poor TTR.
authors.affiliation: Division of Cardiology, Department of Medicine, The University of Hong Kong, Hong Kong SAR, China.
authors.forename: Pak-Hei
authors.initials: PH
authors.lastname: Chan
authors.affiliation: Division of Cardiology, Department of Medicine, The University of Hong Kong, Hong Kong SAR, China.
authors.forename: Duo
authors.initials: D
authors.lastname: Huang
authors.affiliation: Division of Cardiology, Department of Medicine, The University of Hong Kong, Hong Kong SAR, China.
authors.forename: Jo Jo
authors.initials: JJ
authors.lastname: Hai
authors.affiliation: Division of Cardiology, Department of Medicine, The University of Hong Kong, Hong Kong SAR, China; Department of Echocardiography & Non-invasive Cardiology Laboratory, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, Chengdu, China.
authors.forename: Wen-Hua
authors.initials: WH
authors.lastname: Li
authors.affiliation: Department of Echocardiography & Non-invasive Cardiology Laboratory, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, Chengdu, China.
authors.forename: Li-Xue
authors.initials: LX
authors.lastname: Yin
authors.affiliation: Department of Pharmacology and Pharmacy, the University of Hong Kong, Hong Kong SAR, China.
authors.forename: Esther W
authors.initials: EW
authors.lastname: Chan
authors.affiliation: Department of Pharmacology and Pharmacy, the University of Hong Kong, Hong Kong SAR, China.
authors.forename: Ian C K
authors.initials: IC
authors.lastname: Wong
authors.affiliation: Division of Cardiology, Department of Medicine, The University of Hong Kong, Hong Kong SAR, China.
authors.forename: Chu-Pak
authors.initials: CP
authors.lastname: Lau
authors.affiliation: Division of Cardiology, Taipei Veterans General Hospital, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Chern-En
authors.initials: CE
authors.lastname: Chiang
authors.affiliation: Fuwai Hospital, Chinese Academy of Medical Sciences, Beijing, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Zhu
authors.affiliation: Division of Cardiology, Department of Medicine, The University of Hong Kong, Hong Kong SAR, China.
authors.forename: Hung-Fat
authors.initials: HF
authors.lastname: Tse
authors.affiliation: Division of Cardiology, Department of Medicine, The University of Hong Kong, Hong Kong SAR, China. Electronic address: cwdsiu@hku.hk.
authors.forename: Chung-Wah
authors.initials: CW
authors.lastname: Siu
mesh_terms: D000369:Aged, 80 and over; D000925:Anticoagulants / Q000008:administration & dosage / Q000009:adverse effects; D001281:Atrial Fibrillation / Q000150:complications / Q000188:drug therapy / Q000453:epidemiology; D002545:Brain Ischemia / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control; D002681:China / Q000453:epidemiology; D000069604:Dabigatran / Q000008:administration & dosage / Q000009:adverse effects; D005260:Female; D006801:Humans; D020300:Intracranial Hemorrhages / Q000139:chemically induced / Q000175:diagnosis / Q000453:epidemiology; D008297:Male; D017063:Outcome Assessment, Health Care; D020521:Stroke / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control; D014859:Warfarin / Q000008:administration & dosage / Q000009:adverse effects
chemical_list: D000925:Anticoagulants; D014859:Warfarin; D000069604:Dabigatran
keywords: Atrial fibrillation; Chinese; Dabigatran; Elderly