Utility of the assessment of echogenicity in the identification of symptomatic carotid artery atheroma plaques in ischemic stroke patients

Abstract

Background and purpose: Echogenicity of atheroma carotid plaques is related to a higher risk of stroke. Clinical and subjective ultrasound criteria are used to identify symptomatic plaques, but the standardized grayscale median (GSM) value may be an objective tool for this diagnosis. Our aim was to analyze the utility of assessing the echogenicity of atheroma carotid plaques in the identification of symptomatic plaques.

Methods: Observational prospective study with inclusion of acute noncardioembolic anterior cerebral circulation ischemic stroke patients. Only patients with bilateral atheroma plaques were included. Echogenicity of plaques was measured by a digital and standardized grayscale system in carotid ultrasound B-mode (longitudinal projection) conducted within the first week after admission.

Results: Sixty-six patients were included and 132 plaques were examined. Symptomatic atheroma plaques were less echogenic than asymptomatic ones (GSM 20.0 vs. 29.0; p = 0.002). A ROC curve analysis showed the predictive value of GSM with an AUC of 0.707 (95% CI 0.592-0.823; p = 0.002) and pointed to a value of 24.4 as the optimal cut-off level to identify a plaque as symptomatic (74% sensitivity; 67% specificity). This GSM cut-off point remained significantly associated with a high probability of symptomatic plaque even after the inclusion of the degree of carotid stenosis (either >70% or >50%) in the multivariate logistic regression models.

Conclusions: The assessment of echogenicity of atheroma carotid plaques by the GSM value combined with clinical characteristics and stenosis degree may be useful in the identification of symptomatic plaques.