title: Low rates of acute recanalization with intravenous recombinant tissue plasminogen activator in ischemic stroke: real-world experience and a call for action.
abstract: OBJECTIVE
  Acute rates of recanalization after intravenous (IV) recombinant tissue plasminogen activator (rt-PA) in proximal vessel occlusion have been estimated sparingly, typically using transcranial Doppler (TCD). We aimed to study acute recanalization rates of IV rt-PA in CT angiogram-proven proximal (internal carotid artery [ICA], M1 middle cerebral artery [MCA], M2-MCA, and basilar artery) occlusions and their effects on outcome.
  
  
  METHODS
  The CT angiogram database of the Calgary stroke program was reviewed for the period 2002 to 2009. All patients with proximal vessel occlusions receiving IV rt-PA who were assessed for recanalization by TCD or angiogram (for acute endovascular treatment) were included for analysis. Rates of acute recanalization as observed on TCD/first run of angiogram and postendovascular therapy recanalization rates were noted. Modified Rankin Scale score ≤2 at 3 months was used as a good outcome.
  
  
  RESULTS
  Among 1341 patients in the CT angiogram database, 388 patients with proximal occlusion were identified. Of these, 216 patients had received IV rt-PA; 127 patients underwent further imaging to assess recanalization. Among the patients undergoing TCD (n=46) and cerebral angiogram (n=103), only 27 (21.25%) patients had acute recanalization. By occlusion subtype, the rates of recanalization were: distal ICA (with or without ICA neck occlusion or stenotic disease) 1 of 24 (4.4%); M1-MCA (with or without ICA neck occlusion or stenotic disease) 21 of 65 (32.3%); M2-MCA 4 of 13 (30.8%); and basilar artery 1 of 25 (4%). Onset to rt-PA time was comparable in patients with and without recanalization. Recanalization (P<0.0001; risk ratio, 2.7; 95% confidence interval, 1.5-4.6) was the strongest predictor of outcome (adjusted for age and National Institutes of Health Stroke Scale score).
  
  
  CONCLUSIONS
  A low rate of acute recanalization was observed with IV rt-PA in proximal vessel occlusions identified by baseline CT angiogram. Recanalization was the strongest predictor of good outcome.
authors.affiliation: Department of Clinical Neurosciences, Foothills Hospital, University of Calgary, Calgary, Alberta, Canada. rohitbhatia71@yahoo.com
authors.forename: Rohit
authors.initials: R
authors.lastname: Bhatia
authors.forename: Michael D
authors.initials: MD
authors.lastname: Hill
authors.forename: Nandavar
authors.initials: N
authors.lastname: Shobha
authors.forename: Bijoy
authors.initials: B
authors.lastname: Menon
authors.forename: Simerpreet
authors.initials: S
authors.lastname: Bal
authors.forename: Puneet
authors.initials: P
authors.lastname: Kochar
authors.forename: Tim
authors.initials: T
authors.lastname: Watson
authors.forename: Mayank
authors.initials: M
authors.lastname: Goyal
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Demchuk
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002545:Brain Ischemia / Q000000981:diagnostic imaging / Q000188:drug therapy*; D002533:Cerebral Angiography; D005260:Female; D005343:Fibrinolytic Agents / Q000627:therapeutic use; D006801:Humans; D008297:Male; D008875:Middle Aged; D011994:Recombinant Proteins / Q000627:therapeutic use*; D020521:Stroke / Q000000981:diagnostic imaging / Q000188:drug therapy*; D010959:Tissue Plasminogen Activator / Q000627:therapeutic use*; D016896:Treatment Outcome
chemical_list: D005343:Fibrinolytic Agents; D011994:Recombinant Proteins; D010959:Tissue Plasminogen Activator