title: Capillary Index Score in acute ischemic stroke: interobserver reliability and correlation with neurological outcomes.
abstract: BACKGROUND
  Collateral blood flow has been identified as a possible factor to evaluate when predicting neurological outcomes or selecting patients for endovascular therapy in acute ischemic stroke. The Capillary Index Score (CIS) has recently been proposed as a tool to select patients with sufficient collateral blood flow for vascularization and to predict good neurological outcomes. We investigated the inter-rater agreement among reviewers of CIS and compared consensus scores to neurological outcomes.
  
  
  METHODS
  We conducted a retrospective review of 29 randomly selected patients undergoing endovascular therapy for an occlusion in the middle cerebral artery or intracranial internal carotid artery. Patients' angiograms were reviewed by four reviewers of varying experience levels and given a CIS ranging from 0-3. A favorable CIS was 2 or 3 and an unfavorable CIS was 0 or 1. The inter-agreement of the reviewers was calculated using the κ statistic. A consensus CIS was compared with good neurological outcome, defined as modified Rankin Scale scores (mRS≤2) at 90 days.
  
  
  RESULTS
  The agreement between reviewers for the CIS ranged from κ=0.66-0.97, indicating good to very good agreement. 92% of patients with favorable CIS had a positive neurological outcome compared to only 14% of unfavorable CIS patients. The number of patients with a favorable neurological outcome (mRS≤2) at 90 days was higher in the favorable CIS group (P<0.0001).
  
  
  CONCLUSIONS
  CIS was a reproducible metric among physicians of varying experiences. Favorable CIS scores were a predictor of good neurological outcome and lower rates of intracranial hemorrhage. We believe that the Capillary Index Score can be used alongside other tools to improve patient selection for endovascular treatment.
authors.affiliation: Mayo Medical School, Rochester, MN, USA - jagani.manoj@mayo.edu.
authors.forename: Manoj
authors.initials: M
authors.lastname: Jagani
authors.affiliation: Department of Radiology, Mayo Clinic, Rochester, MN, USA.
authors.forename: Waleed
authors.initials: W
authors.lastname: Brinjikji
authors.affiliation: Department of Radiology, Mayo Clinic, Rochester, MN, USA.
authors.forename: Aymeric M
authors.initials: AM
authors.lastname: Rouchaud
authors.affiliation: Department of Radiology, Mayo Clinic, Rochester, MN, USA.|Department of Neurosurgery, Mayo Clinic, Rochester, MN, USA.
authors.forename: Harry J
authors.initials: HJ
authors.lastname: Cloft
authors.affiliation: Department of Radiology, Mayo Clinic, Rochester, MN, USA.|Department of Neurosurgery, Mayo Clinic, Rochester, MN, USA.
authors.forename: David F
authors.initials: DF
authors.lastname: Kallmes
mesh_terms: D000368:Aged; D002545:Brain Ischemia / Q000000981:diagnostic imaging*; D002340:Carotid Artery Diseases / Q000000981:diagnostic imaging*; D002533:Cerebral Angiography / Q000592:standards*; D003097:Collateral Circulation / Q000502:physiology*; D032921:Consensus; D057510:Endovascular Procedures / Q000592:standards*; D005260:Female; D006801:Humans; D020244:Infarction, Middle Cerebral Artery / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D018579:Patient Selection; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012720:Severity of Illness Index; D020521:Stroke / Q000000981:diagnostic imaging*