Carotid plaque echogenicity predicts cerebrovascular symptoms: a systematic review and meta-analysis

Many reports have shown an association between hypoechoic (echolucent) carotid atherosclerotic plaques and unstable features. In this meta-analysis our aim was to determine the role of carotid plaque echogenicity in predicting future cerebrovascular (CV) symptoms.

Electronic databases (PubMed, MEDLINE, EMBASE and Cochrane Center Register) up to September 2015 were systematically searched. Studies with ultrasound-based characterization of carotid artery plaque echogenicity and its association with focal neurological symptoms of vascular origin were eligible for analysis. In the meta-analysis, heterogeneity was measured using I(2) statistics and publication bias was evaluated using the Begg-Mazumdar test. In addition several comparisons between subgroups were performed.

Of 1387 identified reports, eight studies with asymptomatic patients and three studies with symptomatic patients were meta-analyzed. Pooled analysis showed an association between echolucent carotid plaques and future CV events in asymptomatic patients [relative risk 2.72 (95% confidence interval 1.86-3.96)] and recurrent symptoms in symptomatic patients [relative risk 2.97 (95% confidence interval 1.85-4.78)]. The association was preserved for all stenosis degrees in asymptomatic patients, whilst patients with echolucent plaques and severe stenosis were at higher risk of future events. Also, computer-assisted methods for assessment of carotid plaque echogenicity and studies analyzing ultrasound data collected after the year 2000 showed better prediction.

In asymptomatic and symptomatic patients, analysis of carotid plaque echogenicity could identify those at high risk of CV events.