Prediction of high-risk plaque development and plaque progression with the carotid atherosclerosis score

Abstract

Objectives: The goal of this prospective study was to evaluate the carotid atherosclerosis score (CAS) for predicting the development of high-risk plaque features and plaque burden progression.

Background: Previous studies have shown that carotid intraplaque hemorrhage (IPH) and a disrupted luminal surface (DLS), as identified by using magnetic resonance imaging, are associated with greater risk for cerebrovascular events. On the basis of data from a large cross-sectional study, a scoring system was developed to determine which plaque features are associated with the presence of IPH and DLS. However, the predictive value of CAS has not been previously tested in a prospective, longitudinal study.

Methods: A total of 120 asymptomatic subjects with 50% to 79% carotid stenosis underwent carotid magnetic resonance imaging scans at baseline and 3 years thereafter. Presence of IPH and DLS, wall volume, maximum wall thickness, and maximum percent lipid-rich necrotic core area were measured at both time-points. Baseline CAS values were calculated on the basis of previously published criteria.

Results: Of the 73 subjects without IPH or DLS at baseline, 9 (12%) developed 1 or both of these features during follow-up. There was a significant increasing trend between CAS and the development of new DLS (p < 0.001) and with plaque burden progression (p = 0.03) but not with the development of new IPH (p = 0.3). Percent carotid stenosis was not significantly associated with new DLS (p = 0.2), new IPH (p = 0.1), or plaque progression (p = 0.6).

Conclusions: CAS was found to have a significant increasing relationship with incident DLS and plaque progression in this prospective study. CAS can potentially provide improved risk stratification beyond luminal stenosis.

Keywords: carotid atherosclerosis score; disrupted luminal surface; plaque progression; stenosis.