title: Alberta Stroke Program early computed tomography score to select patients for endovascular treatment: Interventional Management of Stroke (IMS)-III Trial.
abstract: OBJECTIVE
  The Interventional Management of Stroke (IMS)-III trial randomized patients with acute ischemic stroke to intravenous tissue-type plasminogen activator (tPA) plus endovascular therapy versus intravenous tPA therapy alone within 3 hours from symptom onset. A predefined secondary hypothesis was that subjects with significant early ischemic change on the baseline scan would not respond to endovascular therapy.
  
  
  METHODS
  The primary outcome was 90-day modified Rankin Scale score 0 to 2. The baseline and follow-up computed tomographic (CT) scan images were reviewed centrally and blinded to any clinical information. We assessed whether the baseline Alberta Stroke Program Early CT Score (ASPECTS) predicted outcome and interacted with study treatment. We analyzed subgroups defined by time from onset to intravenous tPA initiation and baseline occlusion status at a prespecified α=0.01.
  
  
  RESULTS
  Baseline demographic and clinical characteristics of 656 randomized patients were similar between subjects with a baseline ASPECTS 8 to 10 (58% of the study sample) versus 0 to 7. Subjects with ASPECTS 8 to 10 were almost twice as likely (relative risk, 1.8; 99% confidence interval, 1.4-2.4) to achieve a favorable outcome. There was insufficient evidence of a treatment-by-ASPECTS interaction. In those treated with onset to intravenous tPA <120 minutes, in CT angiography-proven internal carotid artery or middle cerebral artery occlusion, and in both, results were similar. The probability of achieving recanalization (arterial occlusion lesion, 2-3) of the primary arterial occlusive lesion (relative risk, 1.3; 99% confidence interval, 1.0-1.8) or achieving thrombolysis in cerebral ischemia score 2b/3 reperfusion (relative risk 2.0; 99% confidence interval, 1.2-3.2) was higher among subjects with higher ASPECTS.
  
  
  CONCLUSIONS
  ASPECTS is a strong predictor of outcome and a predictor of reperfusion. ASPECTS did not identify a subpopulation of subjects that particularly benefitted from endovascular therapy immediately after routine intravenous tPA.
  
  
  BACKGROUND
  http://www.clinicaltrials.gov. Unique identifier: NCT00359424.
authors: From the Calgary Stroke Program, Department of Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada.
authors: Michael D
authors: MD
authors: Hill
authors: Andrew M
authors: AM
authors: Demchuk
authors: Mayank
authors: M
authors: Goyal
authors: Tudor G
authors: TG
authors: Jovin
authors: Lydia D
authors: LD
authors: Foster
authors: Thomas A
authors: TA
authors: Tomsick
authors: Rüdiger
authors: R
authors: von Kummer
authors: Sharon D
authors: SD
authors: Yeatts
authors: Yuko Y
authors: YY
authors: Palesch
authors: Joseph P
authors: JP
authors: Broderick
mesh_terms: D000368:Aged; D001157:Arterial Occlusive Diseases / Q000000981:diagnostic imaging / Q000628:therapy; D002545:Brain Ischemia / Q000000981:diagnostic imaging* / Q000628:therapy*; D019090:Case Management; D002533:Cerebral Angiography; D015897:Comorbidity; D016001:Confidence Intervals; D057510:Endovascular Procedures / Q000379:methods*; D005260:Female; D005343:Fibrinolytic Agents / Q000627:therapeutic use; D006801:Humans; D008297:Male; D008875:Middle Aged; D018579:Patient Selection; D011237:Predictive Value of Tests; D015424:Reperfusion; D012306:Risk; D020521:Stroke / Q000000981:diagnostic imaging* / Q000628:therapy*; D015912:Thrombolytic Therapy; D010959:Tissue Plasminogen Activator / Q000627:therapeutic use; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016896:Treatment Outcome
chemical_list: D005343:Fibrinolytic Agents; D010959:Tissue Plasminogen Activator
keywords: computed tomography scanner, x-ray; stroke; thrombolysis, therapeutic