title: Identification of high-risk carotid artery stenosis: motion of intraplaque contents detected using B-mode ultrasonography.
abstract: OBJECTIVE
  Identification of the risk of rupture and vulnerability of arterial plaque is not yet clearly understood. The aim of this study was to assess the clinical features of the motion of intraplaque contents (MIC) detected by B-mode ultrasonography. The MIC is characterized by the peculiar movement of the intraplaque contents that is not synchronized with the heartbeat; however, the movement of the carotid artery (CA) wall depends on the heartbeat.
  
  
  METHODS
  From January 2008 to November 2010, 1798 consecutive patients with transient ischemic attacks (TIAs) or acute ischemic stroke underwent CA ultrasonography for the examination of the MIC. Patients with CA stenosis greater than 50% were followed up until they underwent carotid endarterectomy or CA angioplasty and stent placement. If neither of these procedures were used, the patients were followed up at 90 days. Chi-square and Mann-Whitney tests were performed to compare the categorical and continuous demographic data and risk factors. The effect of the MIC on the rate of recurrent cerebral ischemia was examined using Kaplan-Meier and univariate Cox regression analyses.
  
  
  RESULTS
  One hundred and fifteen patients had CA stenosis greater than 50%. Among these 115 patients, 58 with a total of 59 CA stenoses had MIC. Twenty-four recurrent ischemic events were associated with MIC, whereas only 6 such events occurred in the absence of MIC. The MIC decreased event-free survival (log-rank test = 15.8, p < 0.001); univariate Cox analysis confirmed that MIC increased the risk of a recurrent ischemic event (HR 5.12, 95% CI 2.08-12.58; p < 0.001).
  
  
  CONCLUSIONS
  The MIC is one of the findings of vulnerable plaques. The MIC is more useful in predicting the recurrence of TIAs or ischemic events in patients with symptomatic CA stenosis.
authors: Department of Neurosurgery, Kashiwaba University Hospital, Sapporo, Japan. gktqx702@yahoo.co.jp
authors: Daina
authors: D
authors: Kashiwazaki
authors: Tetsuyuki
authors: T
authors: Yoshimoto
authors: Taisei
authors: T
authors: Mikami
authors: Mutsuko
authors: M
authors: Muraki
authors: Shin
authors: S
authors: Fujimoto
authors: Kagari
authors: K
authors: Abiko
authors: Sadao
authors: S
authors: Kaneko
mesh_terms: D000368:Aged; D017130:Angioplasty; D016893:Carotid Stenosis / Q000150:complications* / Q000000981:diagnostic imaging* / Q000628:therapy; D016894:Endarterectomy, Carotid; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D002546:Ischemic Attack, Transient / Q000453:epidemiology*; D053208:Kaplan-Meier Estimate; D008297:Male; D012008:Recurrence; D012044:Regression Analysis; D012189:Retrospective Studies; D012307:Risk Factors; D015607:Stents; D020521:Stroke / Q000453:epidemiology*; D018084:Ultrasonography, Interventional