title: Subtherapeutic international normalized ratio in warfarin-treated patients increases the risk for symptomatic intracerebral hemorrhage after intravenous thrombolysis.
abstract: OBJECTIVE
  There is uncertainty whether warfarin-treated patients (despite international normalized ratio < 1.7) have increased risks of symptomatic intracerebral hemorrhage after intravenous thrombolysis.
  
  
  METHODS
  Vascular risk factors, stroke subtype, and outcome measures were compared between warfarin- and nonwarfarin-treated patients undergoing acute thrombolysis within 3 hours of symptom onset.
  
  
  RESULTS
  From 212 patients (mean age, 74 ± 14 years; 50% men) studied, 14 (6.5%) had prior warfarin use. After adjusting for age, baseline National Institutes of Health Stroke Scale, and stroke subtype, warfarin-treated patients had significantly increased risks of developing symptomatic intracerebral hemorrhage (adjusted OR, 14.7; 95% CI, 1.3 to 54.3). A trend for poorer stroke recovery and increased mortality was observed in warfarin-treated patients on univariate, but not on multivariable, analyses.
  
  
  CONCLUSIONS
  Warfarin-treated patients with stroke have increased risks of symptomatic intracerebral hemorrhage after thrombolytic treatment. These data raise safety concerns of thrombolytic treatment in warfarin-treated patients with subtherapeutic international normalized ratio.
authors.affiliation: Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA. raymond_seet@nus.edu.sg
authors.forename: Raymond C S
authors.initials: RC
authors.lastname: Seet
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
authors.forename: S Arthur
authors.initials: SA
authors.lastname: Moore
authors.forename: Eelco F
authors.initials: EF
authors.lastname: Wijdicks
authors.forename: Alejandro A
authors.initials: AA
authors.lastname: Rabinstein
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002545:Brain Ischemia / Q000188:drug therapy; D002543:Cerebral Hemorrhage / Q000209:etiology*; D005260:Female; D005343:Fibrinolytic Agents / Q000009:adverse effects* / Q000627:therapeutic use; D006801:Humans; D007262:Infusions, Intravenous; D019934:International Normalized Ratio; D008297:Male; D008875:Middle Aged; D012306:Risk; D020521:Stroke / Q000188:drug therapy; D015912:Thrombolytic Therapy / Q000009:adverse effects*; D010959:Tissue Plasminogen Activator / Q000009:adverse effects* / Q000627:therapeutic use; D016896:Treatment Outcome; D014859:Warfarin / Q000009:adverse effects* / Q000627:therapeutic use
chemical_list: D005343:Fibrinolytic Agents; D014859:Warfarin; D010959:Tissue Plasminogen Activator