ABSTRACT NUMBER: ESOC2026A2149 CAROTID PLAQUE CALCIFICATION CHARACTERISTICS ON CTA ARE ASSOCIATED WITH SYMPTOMATOLOGY INDEPENDENT OF STENOSIS SEVERITY

Abstract Background and aims Extracranial carotid artery disease accounts for approximately 15% of ischemic strokes. Conventional risk stratification, mainly based on stenosis, inadequately reflects plaque vulnerability. Incorporating plaque composition, particularly calcification, may improve risk assessment. Plaque calcifications remain ambiguous, presenting stabilizing or destabilizing features. This study evaluated whether quantitative and morphological calcification characteristics on CTA are associated with plaque vulnerability independent of stenosis severity. Methods This single-center retrospective cohort analyzed 1,142 patients (2015–2024) who underwent carotid revascularization. Preoperative CTA quantified calcified volume, peak calcium density, and a novel volume-weighted calcium score, and classified calcification morphology into six phenotypes. Associations with symptomatology (ischemic stroke, transient ischemic attack, or amaurosis fugax) were assessed using multivariable logistic regression adjusted for sex, diabetes, smoking, heart failure, and stenosis degree. Results The cohort included 228 asymptomatic and 321 symptomatic patients. Symptomatic plaques had lower calcium scores (569 vs 628 HU, P < 0.001), peak densities (1,162 vs 1,788 HU, P = 0.013), and calcification volumes (238 vs 286 mm3, P = 0.037). The ‘positive rim’ sign was more frequent in symptomatic plaques (33.7% vs 23.9%), while sheet-like calcifications predominated in asymptomatic plaques (16.1% vs 9.4%). After adjusting for confounders, log-transformed calcium score remained associated with symptomatic status (OR 0.46; 95% CI, 0.26–0.79; P = 0.005). Conclusions Calcification characteristics potentially help identify vulnerable carotid plaques. Lower calcium scores, peak densities, and volumes, along with a positive rim sign, characterized vulnerable plaques. Incorporating quantitative and morphological calcification characteristics may enhance the identification of vulnerable plaques and stratification of ischemic stroke risk. Conflict of interest Franziska Röder: nothing to disclose.