title: Eccentric stenosis of the carotid artery associated with ipsilateral cerebrovascular events.
abstract: OBJECTIVE
  Eccentric stenosis of the coronary artery is associated with plaque disruption and acute coronary syndrome. The purpose of the present study was to determine whether eccentric stenosis of the carotid artery contributes to cerebrovascular events.
  
  
  METHODS
  Of 6859 patients with vascular diseases who underwent duplex carotid ultrasonography, we studied 512 internal carotid arteries in 441 patients who had a maximum area stenosis at or more than 70%, which corresponds with approximately 50% or more by the NASCET method. The maximal (A) and minimal wall thicknesses (B) were measured on cross-sectional sonography images, and an eccentricity index was calculated using the following formula: (A - B)/A. Arteries in the lowest quartile of the eccentricity index (<0.69) were defined as having a concentric stenosis, whereas the others were defined as having eccentric stenosis. The underlying clinical characteristics and plaque morphologies, as well as the occurrence of ipsilateral ischemic stroke or transient ischemic attack in the preceding year, were compared between patients with eccentric and concentric stenosis.
  
  
  RESULTS
  Patient characteristics and plaque morphology were similar between the 2 groups. Cerebrovascular events occurred more frequently ipsilaterally to the artery with eccentric stenosis (13.5%) than to the artery with concentric stenosis (5.5%; P = .013); the difference was more evident when cerebrovascular events of presumed carotid arterial origin were assessed (P = .005). After adjusting for risk factors and plaque morphology, eccentric stenosis was independently related to the presence of recent cerebrovascular events (odds ratio = 2.76; 95% confidence interval = 1.19-6.40).
  
  
  CONCLUSIONS
  In patients with an area carotid stenosis of 70% or more, eccentric plaque was associated with a significantly increased incidence of ipsilateral cerebrovascular events compared with patients with concentric stenosis.
authors.affiliation: Cerebrovascular Division, Department of Medicine, National Cardiovascular Center, Suita, Osaka, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Ohara
authors.forename: K
authors.initials: K
authors.lastname: Toyoda
authors.forename: R
authors.initials: R
authors.lastname: Otsubo
authors.forename: K
authors.initials: K
authors.lastname: Nagatsuka
authors.forename: Y
authors.initials: Y
authors.lastname: Kubota
authors.forename: M
authors.initials: M
authors.lastname: Yasaka
authors.forename: H
authors.initials: H
authors.lastname: Naritomi
authors.forename: K
authors.initials: K
authors.lastname: Minematsu
mesh_terms: D000368:Aged; D016893:Carotid Stenosis / Q000175:diagnosis* / Q000453:epidemiology*; D002561:Cerebrovascular Disorders / Q000175:diagnosis* / Q000453:epidemiology*; D015897:Comorbidity; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D015995:Prevalence; D015203:Reproducibility of Results; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D012680:Sensitivity and Specificity