Carotid Plaque Calcification Characteristics on Computed Tomography Angiography Are Associated With Symptomatology Beyond Stenosis Severity: A Retrospective Observational Cohort Study.

OBJECTIVE

To evaluate quantitative and morphologic calcification characteristics on computed tomography angiography (CTA) and their association with carotid plaque symptomatology.

BACKGROUND

Carotid artery disease accounts for approximately 15% of ischemic strokes. Current risk stratification relies primarily on stenosis severity, which incompletely reflects plaque-related risk. Calcification is a key plaque feature with both stabilizing and destabilizing properties, yet its clinical relevance remains incompletely understood.

METHODS

In this single-center retrospective cohort study, 1,142 patients undergoing carotid revascularization (2015-2024) were screened, of whom 500 patients (1,000 carotid arteries) met inclusion criteria. Calcifications were quantified using total calcified volume, peak calcium density, and a novel volume‑weighted calcium score, and classified into 6 phenotypes. Associations with symptomatology (ischemic stroke, transient ischemic attack, amaurosis fugax) were assessed using generalized estimating equations adjusted for stenosis severity, vascular risk factors, and medical therapy.

RESULTS

Among 1000 carotid arteries, 732 were asymptomatic and 268 symptomatic. Symptomatic plaques had lower calcium scores (567 vs. 599 HU; P=0.039), greater calcified volumes (255 vs. 221 mm³; P=0.044), and the positive rim sign dominated (37.3% vs. 13.4%; P<0.001). After multivariable adjustment, higher calcium score was associated with lower odds of symptomatology (aOR: 0.93 per 100‑HU increase; 95% CI: 0.86-0.99; P=0.047), whereas positive rim sign was associated with higher odds (aOR: 2.33; 95% CI: 1.59-3.41; P<0.001).

CONCLUSIONS

CTA-derived quantitative and morphologic calcification characteristics are independently associated with carotid plaque symptomatology beyond stenosis severity, which may refine risk stratification in carotid artery disease.