title: Dabigatran and warfarin in vitamin K antagonist-naive and -experienced cohorts with atrial fibrillation.
abstract: BACKGROUND
  The comparison of anticoagulants dabigatran and warfarin might be most equitable in vitamin K antagonist (VKA)-naive patients.
  
  
  RESULTS
  Warfarin and 2 doses of dabigatran-110 mg BID (D110) and 150 mg BID (D150)-were compared in a balanced population of VKA-naive (≤62 days of lifetime VKA exposure, with 33% never prescribed a VKA) and VKA-experienced patients with atrial fibrillation (n=18 113). For VKA-naive and -experienced patients assigned warfarin, the time in therapeutic range (international normalized ratio 2.0 to 3.0) was 62% and 67%, respectively, and 61% and 66% for those never and ever prescribed a VKA. In VKA-naive patients, stroke and systemic embolism rates were 1.57%, 1.07%, and 1.69% per year for D110, D150, and warfarin, respectively. D110 was similar to warfarin (P=0.65); D150 was superior (P=0.005). Major bleeding rates were 3.11%, 3.34%, and 3.57% per year, respectively. D110 and D150 were similar to warfarin (P=0.19 and P=0.55). Intracranial bleeding rates were 0.19%, 0.33%, and 0.73% per year, respectively. D110 and D150 were lower than warfarin (P<0.001 and P=0.005). In VKA-experienced patients, stroke and systemic embolism rates were 1.51%, 1.15%, and 1.74% per year for D110, D150, and warfarin, respectively. D110 was similar to warfarin (P=0.32); D150 was superior (P=0.007). Major bleeding rates were 2.66%, 3.30%, and 3.57% per year, respectively. D110 was lower than warfarin (P=0.003); D150 was similar (P=0.41). Intracranial bleeding rates were 0.26%, 0.32%, and 0.79% per year, respectively. D110 and D150 were lower than warfarin (P<0.001 for both). Results were similar for patients never on a VKA.
  
  
  CONCLUSIONS
  Previous VKA exposure does not influence the benefits of dabigatran at either dose compared with warfarin.
  
  
  BACKGROUND
  http://www.clinicaltrials.gov. Unique identifier: NCT00262600.
authors.affiliation: Lankenau Institute for Medical Research, 100 Lancaster Ave, Suite G36, Wynnewood, PA 19096, USA. ezekowitzm@mlhs.org
authors.forename: Michael D
authors.initials: MD
authors.lastname: Ezekowitz
authors.forename: Lars
authors.initials: L
authors.lastname: Wallentin
authors.forename: Stuart J
authors.initials: SJ
authors.lastname: Connolly
authors.forename: Amit
authors.initials: A
authors.lastname: Parekh
authors.forename: Michael R
authors.initials: MR
authors.lastname: Chernick
authors.forename: Janice
authors.initials: J
authors.lastname: Pogue
authors.forename: Timothy H
authors.initials: TH
authors.lastname: Aikens
authors.forename: Sean
authors.initials: S
authors.lastname: Yang
authors.forename: Paul A
authors.initials: PA
authors.lastname: Reilly
authors.forename: Gregory Y H
authors.initials: GY
authors.lastname: Lip
authors.forename: Salim
authors.initials: S
authors.lastname: Yusuf
mesh_terms: D000368:Aged; D000925:Anticoagulants / Q000009:adverse effects / Q000627:therapeutic use*; D001281:Atrial Fibrillation / Q000150:complications / Q000188:drug therapy*; D001562:Benzimidazoles / Q000009:adverse effects / Q000627:therapeutic use*; D000069604:Dabigatran; D004305:Dose-Response Relationship, Drug; D004617:Embolism / Q000517:prevention & control; D005260:Female; D005500:Follow-Up Studies; D006471:Gastrointestinal Hemorrhage / Q000453:epidemiology; D006801:Humans; D020300:Intracranial Hemorrhages / Q000453:epidemiology; D008297:Male; D011725:Pyridines / Q000009:adverse effects / Q000627:therapeutic use*; D012307:Risk Factors; D020521:Stroke / Q000517:prevention & control; D016896:Treatment Outcome; D014812:Vitamin K / Q000037:antagonists & inhibitors*; D014859:Warfarin / Q000009:adverse effects / Q000627:therapeutic use*
chemical_list: D000925:Anticoagulants; D001562:Benzimidazoles; D011725:Pyridines; D014812:Vitamin K; D014859:Warfarin; D000069604:Dabigatran