title: Tandem internal carotid artery/middle cerebral artery occlusion: an independent predictor of poor outcome after systemic thrombolysis.
abstract: OBJECTIVE
  Although tandem internal carotid artery/middle cerebral artery (MCA; TIM) occlusion has been associated with low recanalization rate after IV tissue plasminogen activator (tPA), its independent contribution on stroke outcome remains unknown. Moreover, whether the relative resistance to thrombolysis in tandem lesions varies depending on the location of MCA clot remains uncertain.
  
  
  METHODS
  Two hundred and twenty-one consecutive stroke patients with an acute MCA occlusion treated with IV tPA were studied. Emergent carotid artery ultrasound and transcranial Doppler (TCD) examinations were performed in all patients before treatment. Recanalization was assessed on TCD at 2 hours of tPA bolus. National Institutes of Health Stroke Scale (NIHSS) scores were obtained at baseline and after 24 hours. Modifed Rankin Scale score was used to assess outcome at 3 months.
  
  
  RESULTS
  Median prebolus NIHSS score was 16 points. On TCD, 156 (71.6%) patients had a proximal and 65 (29.4%) a distal MCA occlusion. TIM occlusion was identified in 44 (19.9%) patients. Eighteen (41.9%) patients with and 123 (69.5%) without TIM lesions achieved an MCA recanalization (P=0.01). In a logistic regression model, hyperglycemia >140 mg/dL (odds ratio [OR] 3.3, 95% CI, 1.6 to 6.8) and the presence of TIM occlusion (OR 2.8, 95% CI, 1.1 to 6.9) emerged as independent predictors of absence of recanalization. However, the independent contribution of TIM lesions on poor response to thrombolysis varied depending on the location of MCA occlusion. TIM occlusion independently predicted resistance to thrombolysis in patients with proximal (OR 4.63, 95% CI, 1.79 to 11.96), but not in those with distal MCA occlusion. Patients with TIM occlusion had worse short- (P<0.0001) and long-term (P<0.0001) clinical outcome.
  
  
  CONCLUSIONS
  TIM occlusion independently predicts poor outcome after IV thrombolysis. However, its impact varies depending on the location of MCA clot. Therefore, emergent carotid ultrasound plus TCD examinations may improve the selection of patients for more aggressive reperfusion strategies.
authors.affiliation: Brain Hemodynamics Lab, Stroke Unit, Department of Neurology, Hospital Vall d'Hebron, Passeig Vall d'Hebron 119-129, 08035 Barcelona, Spain.
authors.forename: Marta
authors.initials: M
authors.lastname: Rubiera
authors.forename: Marc
authors.initials: M
authors.lastname: Ribo
authors.forename: Raquel
authors.initials: R
authors.lastname: Delgado-Mederos
authors.forename: Esteban
authors.initials: E
authors.lastname: Santamarina
authors.forename: Pilar
authors.initials: P
authors.lastname: Delgado
authors.forename: Joan
authors.initials: J
authors.lastname: Montaner
authors.forename: José
authors.initials: J
authors.lastname: Alvarez-Sabín
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Molina
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001157:Arterial Occlusive Diseases / Q000150:complications* / Q000000981:diagnostic imaging; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging; D005260:Female; D005343:Fibrinolytic Agents / Q000008:administration & dosage / Q000627:therapeutic use; D006801:Humans; D007275:Injections, Intravenous; D008297:Male; D008875:Middle Aged; D020768:Middle Cerebral Artery; D011379:Prognosis; D020521:Stroke / Q000188:drug therapy* / Q000209:etiology*; D015912:Thrombolytic Therapy; D010959:Tissue Plasminogen Activator / Q000008:administration & dosage / Q000627:therapeutic use; D016896:Treatment Outcome; D017585:Ultrasonography, Doppler, Transcranial
chemical_list: D005343:Fibrinolytic Agents; D010959:Tissue Plasminogen Activator