title: Symptomatic intracranial atherosclerosis: outcome of patients who fail antithrombotic therapy.
abstract: OBJECTIVE
  To determine the prognosis of patients with symptomatic intracranial atherosclerosis who fail antithrombotic therapy.
  
  
  BACKGROUND
  The outcome of patients with symptomatic intracranial atherosclerosis who fail antithrombotic therapy is unknown. These patients may represent the target group for investigation of more aggressive therapies such as intracranial angioplasty.
  
  
  METHODS
  The authors performed a chart review and telephone interview of patients with symptomatic intracranial atherosclerosis identified in the Stanford Stroke Center clinical database. A Cox regression model was created to identify factors predictive of failure of antithrombotic therapy. The authors generated Kaplan-Meier survival curves to determine the timing of recurrent TIA, stroke, or death after failure of antithrombotic therapy.
  
  
  RESULTS
  Fifty-two patients had symptomatic intracranial atherosclerosis and fulfilled entry criteria. Twenty-nine of the 52 patients (55.8%) had cerebral ischemic events while receiving an antithrombotic agent (antiplatelet agents [55%], warfarin [31%], or heparin [14%]). In a Cox regression model, older age was an independent predictor of failure of antithrombotic therapy, and warfarin use was associated with a decrease in risk. Recurrent TIA (n = 7), nonfatal/fatal stroke (n = 6/1), or death (n = 1) occurred in 15 of 29 (51.7%) of the patients who failed antithrombotic therapy. The median time to recurrent TIA, stroke, or death was 36 days (95% CI 13 to 59).
  
  
  CONCLUSIONS
  Patients with symptomatic intracranial atherosclerosis who fail antithrombotic therapy have extremely high rates of recurrent TIA/stroke or death. Recurrent ischemic events typically occur within a few months after failure of standard medical therapy. The high recurrence risk observed warrants testing of alternative treatment strategies such as intracranial angioplasty.
authors.affiliation: Stanford Stroke Center, Department of Neurology and Neurological Sciences, Stanford University Medical Center, Palo Alto, CA 94304-0117, USA. vthijs@stanford.edu
authors.forename: V N
authors.initials: VN
authors.lastname: Thijs
authors.forename: G W
authors.initials: GW
authors.lastname: Albers
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000627:therapeutic use; D001241:Aspirin / Q000627:therapeutic use; D005260:Female; D005343:Fibrinolytic Agents / Q000627:therapeutic use*; D005500:Follow-Up Studies; D006493:Heparin / Q000627:therapeutic use; D006801:Humans; D002537:Intracranial Arteriosclerosis / Q000150:complications / Q000175:diagnosis* / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use; D016016:Proportional Hazards Models; D012008:Recurrence; D018570:Risk Assessment; D020521:Stroke / Q000175:diagnosis / Q000209:etiology / Q000401:mortality; D016019:Survival Analysis; D015996:Survival Rate; D017211:Treatment Failure; D016896:Treatment Outcome; D014859:Warfarin / Q000627:therapeutic use
chemical_list: D000925:Anticoagulants; D005343:Fibrinolytic Agents; D010975:Platelet Aggregation Inhibitors; D014859:Warfarin; D006493:Heparin; D001241:Aspirin