Ultrasonic plaque echolucency and emboli signals predict stroke in asymptomatic carotid stenosis

Neurology. 2011 Aug 23;77(8):751-8. doi: 10.1212/WNL.0b013e31822b00a6. Epub 2011 Aug 17.


Objectives: Better methods are required to identify patients with asymptomatic carotid stenosis (ACS) at risk of future stroke. Two potential markers of high risk are echolucent plaque morphology on carotid ultrasound and embolic signals (ES) in the ipsilateral middle cerebral artery on transcranial Doppler ultrasound (TCD). We explored the predictive value of a score based on these 2 measures in the prospective, observational, international multicenter Asymptomatic Carotid Emboli Study.

Methods: A total of 435 recruited subjects with ACS ≥70% had baseline ultrasound images and TCD data available. Subjects were prospectively followed up for 2 years.

Results: A total of 164 (37.7%) plaques were graded as echolucent. Plaque echolucency at baseline was associated with an increased risk of ipsilateral stroke alone (hazard ratio [HR] 6.43, 95% confidence interval [CI] 1.36-30.44, p = 0.019). A combined variable of plaque echolucency and ES positivity at baseline was associated with a markedly increased risk of ipsilateral stroke alone (HR 10.61, 95% CI 2.98-37.82, p = 0.0003). This association remained significant after controlling for risk factors, degree of carotid stenosis, and antiplatelet medication.

Conclusions: Plaque morphology assessed using a simple, and clinically applicable, visual rating scale predicts ipsilateral stroke risk in ACS. The combination of ES detection and plaque morphology allows a greater prediction than either measure alone and identifies a high-risk group with an annual stroke risk of 8%, and a low-risk group with a risk of <1% per annum. This risk stratification may prove useful in the selection of patients with ACS for endarterectomy.

Publication types

  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Carotid Stenosis / complications*
  • Carotid Stenosis / diagnostic imaging*
  • Carotid Stenosis / pathology
  • Chi-Square Distribution
  • Embolism / etiology*
  • Female
  • Functional Laterality
  • Humans
  • International Cooperation
  • Longitudinal Studies
  • Magnetic Resonance Imaging
  • Male
  • Middle Cerebral Artery / diagnostic imaging
  • Middle Cerebral Artery / pathology
  • Predictive Value of Tests
  • Proportional Hazards Models
  • Retrospective Studies
  • Risk Factors
  • Stroke / diagnosis*
  • Stroke / etiology*
  • Tomography, X-Ray Computed
  • Ultrasonography, Doppler, Transcranial*