title: Infarct volume is a pivotal biomarker after intra-arterial stroke therapy.
abstract: OBJECTIVE
  Pretreatment infarct volume appears to predict clinical outcome after intra-arterial therapy. To confirm the importance of infarct size in patients undergoing intra-arterial therapy, we sought to characterize the relationship between final infarct volume (FIV) and long-term functional outcome in a prospective cohort of endovascularly treated patients.
  
  
  METHODS
  From our prospective intra-arterial therapy database, we identified 107 patients with acute ischemic stroke with anterior circulation proximal artery occlusions who underwent final infarct imaging and had 3-month modified Rankin Scale scores. Clinical, imaging, treatment, and outcome data were analyzed.
  
  
  RESULTS
  Mean age was 66.6 years. Median admission National Institutes of Health Stroke Scale score was 17. Reperfusion (Thrombolysis In Cerebral Infarction 2A-3) was achieved in 78 (72.9%) patients. Twenty-seven (25.2%) patients achieved a 3-month good outcome (modified Rankin Scale 0-2), and 30 (28.0%) died. Median FIV was 71.4 cm(3). FIV independently correlated with functional outcome across the entire modified Rankin Scale. In receiver operating characteristic analysis, it was the best discriminator of both good outcome (area under the curve=0.857) and mortality (area under the curve=0.772). A FIV of approximately 50 cm(3) demonstrated the greatest accuracy for distinguishing good versus poor outcome, and a FIV of approximately 90 cm(3) was highly specific for a poor outcome. The interaction term between FIV and age was the only independent predictor of good outcome (P<0.0001). The impact of FIV was accentuated in patients <80 years.
  
  
  CONCLUSIONS
  Among patients with anterior circulation acute ischemic stroke who undergo intra-arterial therapy, final infarct volume is a critical determinant of 3-month functional outcome and appears suitable as a surrogate biomarker in proof-of-concept intra-arterial therapy trials.
authors.affiliation: Departments of Radiology, Massachusetts General Hospital, Boston, MA, USA. ajyoo@partners.org
authors.forename: Albert J
authors.initials: AJ
authors.lastname: Yoo
authors.forename: Zeshan A
authors.initials: ZA
authors.lastname: Chaudhry
authors.forename: Raul G
authors.initials: RG
authors.lastname: Nogueira
authors.forename: Michael H
authors.initials: MH
authors.lastname: Lev
authors.forename: Pamela W
authors.initials: PW
authors.lastname: Schaefer
authors.forename: Lee H
authors.initials: LH
authors.lastname: Schwamm
authors.forename: Joshua A
authors.initials: JA
authors.lastname: Hirsch
authors.forename: R Gilberto
authors.initials: RG
authors.lastname: González
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers; D020520:Brain Infarction / Q000000981:diagnostic imaging* / Q000473:pathology*; D015331:Cohort Studies; D016208:Databases, Factual; D005260:Female; D005343:Fibrinolytic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D006801:Humans; D007262:Infusions, Intravenous; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D059906:Neuroimaging / Q000379:methods; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012189:Retrospective Studies; D020521:Stroke / Q000188:drug therapy*; D015912:Thrombolytic Therapy / Q000379:methods*; D010959:Tissue Plasminogen Activator / Q000008:administration & dosage / Q000627:therapeutic use*; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
chemical_list: D015415:Biomarkers; D005343:Fibrinolytic Agents; D010959:Tissue Plasminogen Activator