title: Interhospital variation in reperfusion rates following endovascular treatment for acute ischemic stroke.
abstract: BACKGROUND
  Patients who have successful reperfusion following endovascular therapy for acute ischemic stroke have improved clinical outcomes. We sought to determine if the chance of successful reperfusion differs among hospitals, and if hospital site is an independent predictor of reperfusion.
  
  
  METHODS
  Nine hospitals recruited patients in the Diffusion and Perfusion Imaging Evaluation for Understanding Stroke Evolution Study 2 (DEFUSE 2), a prospective cohort study of endovascular stroke treatment conducted between 2008 and 2011. Patients were included for analysis if they had a baseline Thrombolysis in Cerebral Infarction (TICI) score of 0 or 1. Successful reperfusion was defined as a TICI reperfusion score of 2b or 3 at completion of the procedure. Collaterals were assessed using the Collateral Flow Grading System and were dichotomized as poor (0-2) or good (3-4). The association between hospital site and successful reperfusion was first assessed in an unadjusted analysis and subsequently in a multivariate analysis that adjusted for predictors of successful reperfusion.
  
  
  RESULTS
  36 of 89 patients (40%) achieved successful reperfusion. The rate of reperfusion varied from 0% to 77% among hospitals in the univariate analysis (χ(2) p<0.001) but hospital site did not remain as an independent predictor of reperfusion in multivariate analysis (p=0.81) after adjustment for the presence of good collaterals (p<0.01) and use of the Merci retriever (p<0.05).
  
  
  CONCLUSIONS
  Reperfusion rates vary among hospitals, which may be related to differences in treatment protocols and patient characteristics. Additional studies are needed to identify all of the factors that underlie this variability as this could lead to strategies that reduce interhospital variability in reperfusion rates and improve clinical outcomes.
authors.affiliation: Stanford Stroke Center, Stanford University Medical Center, Stanford, California, USA.
authors.forename: John T P
authors.initials: JT
authors.lastname: Liggins
authors.affiliation: Stanford Stroke Center, Stanford University Medical Center, Stanford, California, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Mlynash
authors.affiliation: Department of Neurology, University of Pittsburgh Medical Center, Stroke Institute and UPMC Center for Neuroendovascular Therapy, Pittsburgh, Pennsylvania, USA.
authors.forename: Tudor G
authors.initials: TG
authors.lastname: Jovin
authors.affiliation: Department of Radiology, Lucas Magnetic Resonance Spectroscopy and Imaging Center, Stanford University Medical Center, Stanford, California, USA.
authors.forename: Matus
authors.initials: M
authors.lastname: Straka
authors.affiliation: Stanford Stroke Center, Stanford University Medical Center, Stanford, California, USA.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Kemp
authors.affiliation: Department of Radiology, Lucas Magnetic Resonance Spectroscopy and Imaging Center, Stanford University Medical Center, Stanford, California, USA.
authors.forename: Roland
authors.initials: R
authors.lastname: Bammer
authors.affiliation: Stanford Stroke Center, Stanford University Medical Center, Stanford, California, USA.
authors.forename: Michael P
authors.initials: MP
authors.lastname: Marks
authors.affiliation: Stanford Stroke Center, Stanford University Medical Center, Stanford, California, USA.
authors.forename: Gregory W
authors.initials: GW
authors.lastname: Albers
authors.affiliation: Stanford Stroke Center, Stanford University Medical Center, Stanford, California, USA.
authors.forename: Maarten G
authors.initials: MG
authors.lastname: Lansberg
mesh_terms: D000368:Aged; D002545:Brain Ischemia / Q000175:diagnosis / Q000601:surgery*; D016507:Cardiology Service, Hospital / Q000592:standards*; D015331:Cohort Studies; D057510:Endovascular Procedures / Q000592:standards*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D015424:Reperfusion / Q000592:standards*; D020521:Stroke / Q000175:diagnosis / Q000601:surgery*; D016896:Treatment Outcome
keywords: acute stroke; endovascular treatment; hospital; reperfusion; variation