title: Asymptomatic Extracranial Vertebral Artery Disease in Patients with Internal Carotid Artery Stenosis.
abstract: BACKGROUND
  Extracranial vertebral artery disease is seen in patients with internal carotid artery stenosis, although the clinical significance is not well understood.
  
  
  OBJECTIVE
  To determine the prevalence and natural history of extracranial vertebral artery disease in patients with recently symptomatic internal carotid artery stenosis.
  
  
  METHODS
  We analyzed data collected for patients with recently symptomatic internal carotid artery stenosis in the Stent-Protected Angioplasty vs Carotid Endarterectomy trial. We used Cox proportional hazards analysis to compare the relative risk of various endpoints (any stroke, ipsilateral stroke, and death) between the 3 categories of extracranial vertebral artery disease (normal/hypoplastic, moderate/severe stenosis, occlusion) adjusting for age, gender, severity of internal carotid artery stenosis at baseline (<70% and ≥70%), allocated procedure (carotid angioplasty and stent placement or carotid endarterectomy) and hypertension.
  
  
  RESULTS
  Moderate to severe stenosis and occlusion of 1 of both extracranial vertebral arteries were diagnosed in 152 (12.9%) and 57 (4.8%) of 1181 subjects, respectively. Comparing subjects with normal or hypoplastic vertebral artery, there was nonsignificant 30%, 40%, and 50% higher risk of any stroke (hazard ratio [HR] 1.3, 95% confidence interval [CI] 0.7-2.3), ipsilateral stroke (HR 1.4, 95% CI 0.7-2.5), and death (HR 1.5, 95% CI 0.7-3.1) among subjects with moderate to severe vertebral artery stenosis after adjusting for potential confounders.
  
  
  CONCLUSIONS
  There may be an increased risk of stroke and death in patients with symptomatic internal carotid artery stenosis with concurrent asymptomatic extracranial vertebral artery stenosis.
authors.affiliation: Zeenat Qureshi Stroke Institute, St. Cloud, Minnesota.
authors.forename: Adnan I
authors.initials: AI
authors.lastname: Qureshi
authors.affiliation: Department of Neur-ology and Ophthalmology, Michigan State University, Lansing, Michigan.
authors.forename: Saqib A
authors.initials: SA
authors.lastname: Chaudhry
authors.affiliation: Department of Vascular Surgery, Medical Center, Technical University of Munich, Germany.
authors.forename: Henning
authors.initials: H
authors.lastname: Eckstein
authors.affiliation: Department of Radio-logy and Neuroradiology, University of Kiel, Arnold-Heller Str.3, Kiel, Germany.
authors.forename: Olav
authors.initials: O
authors.lastname: Jansen
authors.affiliation: Department of Neurology, Universitä-tsklinikum Heidelberg, University of Heidelberg, Heidelberg, Germany.
authors.forename: Peter A
authors.initials: PA
authors.lastname: Ringleb
mesh_terms: D017130:Angioplasty; D001165:Arteriovenous Malformations / Q000150:complications / Q000000981:diagnostic imaging; D016893:Carotid Stenosis / Q000150:complications / Q000000981:diagnostic imaging / Q000601:surgery; D016894:Endarterectomy, Carotid; D006801:Humans; D016016:Proportional Hazards Models; D014711:Vertebral Artery / Q000002:abnormalities / Q000000981:diagnostic imaging
keywords: Carotid stenosis; Death; Extracranial vertebral artery; Stroke; Vertebral artery occlusion; Vertebral artery stenosis