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

BACKGROUND AND PURPOSE

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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

Ultrasound assessment of carotid plaque echogenicity response to statin therapy: a systematic review and meta-analysis

OBJECTIVE

To evaluate in a systematic review and meta-analysis model the effect of statin therapy on carotid plaque echogenicity assessed by ultrasound.

METHODS

We have systematically searched electronic databases (PubMed, MEDLINE, EMBASE and Cochrane Center Register) up to April, 2015, for studies evaluating the effect of statins on plaque echogenicity. Two researchers independently determined the eligibility of studies evaluating the effect of statin therapy on carotid plaque echogenicity that used ultrasound and grey scale median (GSM) or integrated back scatter (IBS).

RESULTS

Nine out of 580 identified studies including 566 patients' carotid artery data were meta-analyzed for a mean follow up of 7.2 months. A consistent increase in the echogenicity of carotid artery plaques, after statin therapy, was reported. Pooled weighted mean difference % (WMD) on plaque echogenicity after statin therapy was 29% (95% CI 22%-36%), p<0.001, I2=92.1%. In a meta-regression analysis using % mean changes of LDL, HDL and hsCRP as moderators, it was shown that the effects of statins on plaque echogenicity were related to changes in hsCRP, but not to LDL and HDL changes from the baseline. The effect of statins on the plaque was progressive; it showed significance after the first month of treatment, and the echogenicity continued to increase in the following six and 12 months.

CONCLUSIONS

Statin therapy is associated with a favorable increase of carotid plaque echogenicity. This effect seems to be dependent on the period of treatment and hsCRP change from the baseline, independent of changes in LDL and HDL.