title: Baseline National Institutes of Health stroke scale-adjusted time window for intravenous tissue-type plasminogen activator in acute ischemic stroke.
abstract: OBJECTIVE
  The effect of tissue-type plasminogen activator on functional outcome decreases progressively over time. However, given the differential pattern of arterial occlusion, stroke severity, and speed of ischemic lesion growth among candidates for reperfusion, the time window should be adjusted accordingly. We aimed to identify the impact of time-to-treatment according to stroke severity on functional outcome in patients with acute ischemic stroke.
  
  
  METHODS
  We included 581 consecutive patients treated with alteplase according to the European Summary of Product Characteristics criteria. Patients were categorized according to National Institutes of Health Stroke Scale (NIHSS) severity in mild NIHSS (≤8), moderate NIHSS (9-15), and severe stroke NIHSS (≥16). We sequentially analyzed time-to-treatment to achieve favorable outcome (modified Rankin Scale ≤2 at 3 months).
  
  
  RESULTS
  Overall, 19.8% had mild, 30.3% had moderate, and 49.9% had severe stroke. Favorable outcome occurred in 79.1%, 60.8%, and 26.2%, respectively. In patients with mild stroke, younger age (odds ratio [OR], 0.88; 95% confidence intervals [CI], 0.8-0.95), no previous history of stroke (OR, 0.16; 95% CI [0.039-0.65]), and no proximal occlusion (OR, 0.183; 95% CI [0.038-0.89]) independently predicted favorable outcome. In patients with moderate stroke, age (OR, 0.95; 95% CI [0.92-0.98]), no proximal occlusion (OR, 0.362; 95% CI [0.17-0.75]), and time-to-treatment before 120 minutes (OR, 2.70; 95% CI [1.14-6.38]) emerged as independent predictors of favorable outcome. In patients with severe stroke, younger age (OR, 0.96; 95% CI [0.94-0.99]), lower previous modified Rankin Scale (OR, 0.42; 95% CI [0.21-0.82]), and absence of proximal occlusion (OR, 0.48; 95% CI [0.25-0.94]) appeared as independent predictors.
  
  
  CONCLUSIONS
  The impact of time-to-treatment on favorable outcome varies widely depending on baseline stroke severity. The window for favorable outcome was ≤120 min for moderate strokes. However, time-to-treatment seemed unrelated to functional outcome in mild and severe stroke.
authors.affiliation: From the Stroke Unit, Department of Neurology, Vall d'Hebron University Hospital, Vall d'Hebron Research Institute, Departament de Medicina, Universitat Autonoma de Barcelona, Spain.
authors.forename: Marián
authors.initials: M
authors.lastname: Muchada
authors.forename: Marta
authors.initials: M
authors.lastname: Rubiera
authors.forename: David
authors.initials: D
authors.lastname: Rodriguez-Luna
authors.forename: Jorge
authors.initials: J
authors.lastname: Pagola
authors.forename: Alan
authors.initials: A
authors.lastname: Flores
authors.forename: Julia
authors.initials: J
authors.lastname: Kallas
authors.forename: Estela
authors.initials: E
authors.lastname: Sanjuan
authors.forename: Pilar
authors.initials: P
authors.lastname: Meler
authors.forename: Jose
authors.initials: J
authors.lastname: Alvarez-Sabin
authors.forename: Marc
authors.initials: M
authors.lastname: Ribo
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Molina
mesh_terms: D000208:Acute Disease; D000368:Aged; D000369:Aged, 80 and over; D002545:Brain Ischemia / Q000188:drug therapy*; D005260:Female; D005343:Fibrinolytic Agents / Q000008:administration & dosage; D006801:Humans; D007275:Injections, Intravenous; D008297:Male; D008875:Middle Aged; D009316:National Institutes of Health (U.S.) / Q000592:standards*; D011446:Prospective Studies; D012720:Severity of Illness Index; D020521:Stroke / Q000188:drug therapy*; D061665:Time-to-Treatment / Q000592:standards*; D010959:Tissue Plasminogen Activator / Q000008:administration & dosage*; D016896:Treatment Outcome; D014481:United States
chemical_list: D005343:Fibrinolytic Agents; D010959:Tissue Plasminogen Activator
keywords: stroke; thrombolytic therapy; time-to-treatment; tissue-type plasminogen activator