Change in Carotid Plaque Components: A 4-Year Follow-Up Study With Serial MR Imaging

Abstract

Objectives: The goal of this study was to determine how carotid plaque components (e.g., intraplaque hemorrhage [IPH], calcification, lipid core) change over time and which cardiovascular risk factors are associated with the development of each component.

Background: Carotid atherosclerotic plaque components are important markers of plaque vulnerability. How these components change and which factors lead to the development and changes in the components remain unclear.

Methods: A total of 198 participants (mean age 67.5 ± 10.6 years) from the population-based Rotterdam Study, all with carotid wall thickening on ultrasound, underwent 2 magnetic resonance imaging scans for carotid plaque characterization (mean interscan interval 4.1 ± 0.2 years). Presence of IPH, calcification, and lipid-rich necrotic core was assessed on both sides on the baseline and follow-up scans. The association between cardiovascular risk factors and incident carotid plaque components was assessed.

Results: In the 396 arteries, all plaque components significantly changed over time. Incidence of IPH, calcification, and lipid core was, respectively, 18.5%, 59.2%, and 39.6%. The factor most strongly associated with the incidence of IPH was use of antihypertensive drugs (multivariate adjusted odds ratio [OR]: 3.87; 95% confidence interval [CI]: 1.90 to 7.90) and severe hypertension (multivariate adjusted OR: 4.70; 95% CI: 1.50 to 14.80). The incidence of calcification was associated with hypertension (OR: 2.20; 95% CI: 1.07 to 4.40). Higher cholesterol levels were associated with incidence of lipid cores (multivariate adjusted OR per unit increase in cholesterol: 1.40; 95% CI: 1.10 to 1.70).

Conclusions: In these community-dwelling subjects, characteristics of plaque composition changed dramatically within a few years, and cardiovascular risk factors played a major role in these changes. Hypertension and its treatment and serum cholesterol levels were the main risk factors for the development of atherosclerotic plaque components over time.

Keywords: MRI; atherosclerosis; calcification; intraplaque hemorrhage; lipid-rich necrotic core.