title: Use of quantitative magnetic resonance angiography to stratify stroke risk in symptomatic vertebrobasilar disease.
abstract: OBJECTIVE
  Symptomatic vertebrobasilar disease (VBD) carries a high risk of recurrent stroke. We sought to determine whether a management algorithm consisting of quantitative hemodynamic assessment could stratify stroke risk and guide the need for intervention.
  
  
  METHODS
  All patients with symptomatic VBD at our institution are evaluated by a standard protocol including quantitative magnetic resonance angiography (QMRA). Patients are stratified on the basis of the presence or absence of distal flow compromise. Those with low distal flow are offered intervention (surgical or endovascular); all patients receive standard medical therapy. We reviewed the clinical outcome of patients managed with this protocol from 1998 to 2003.
  
  
  RESULTS
  Follow-up was available for 47 of 50 patients over a mean interval of 28 months. Stroke and combined stroke/transient ischemic attack free survival at 2 years was calculated using the Kaplan-Meier curve. Patients with normal distal flow (n=31) had an event-free survival of 100% and 96%, respectively. Comparatively, patients with low distal flow (n=16) experienced a 71% and 53% event-free survival, demonstrating a significantly higher risk of recurrent ischemia (P=0.003). Patients with low flow who subsequently underwent treatment (n=12) had an 82% event-free survival. Cox proportional hazards analysis demonstrated that flow status affected event-free survival regardless of covariates.
  
  
  CONCLUSIONS
  Patients with symptomatic VBD demonstrating low distal flow on QMRA appear to have a high risk of stroke; conversely, those with normal flow seem to have a benign course and may be optimally managed with medical therapy alone.
authors.affiliation: Department of Neurosurgery, University of Illinois at Chicago, 912 S Wood St, Chicago, IL 60612-7329, USA. hanjani@uic.edu
authors.forename: Sepideh
authors.initials: S
authors.lastname: Amin-Hanjani
authors.forename: Xinjian
authors.initials: X
authors.lastname: Du
authors.forename: Meide
authors.initials: M
authors.lastname: Zhao
authors.forename: Katherine
authors.initials: K
authors.lastname: Walsh
authors.forename: Tim W
authors.initials: TW
authors.lastname: Malisch
authors.forename: Fady T
authors.initials: FT
authors.lastname: Charbel
mesh_terms: D000328:Adult; D000368:Aged; D000465:Algorithms; D002545:Brain Ischemia / Q000473:pathology; D002340:Carotid Artery Diseases / Q000175:diagnosis; D002533:Cerebral Angiography / Q000379:methods; D002548:Cerebral Revascularization; D002560:Cerebrovascular Circulation; D003251:Constriction, Pathologic / Q000473:pathology; D018572:Disease-Free Survival; D005260:Female; D006439:Hemodynamics; D006801:Humans; D002546:Ischemic Attack, Transient / Q000473:pathology; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D016016:Proportional Hazards Models; D012008:Recurrence; D012189:Retrospective Studies; D012306:Risk; D012984:Software; D020521:Stroke / Q000473:pathology*; D013997:Time Factors; D016896:Treatment Outcome; D014715:Vertebrobasilar Insufficiency / Q000150:complications / Q000175:diagnosis*