Supplementary Material for: In-depth carotid calcification morphometrics and their temporal changes are associated with cardiovascular risk factors in patients with recent ischemic event: The Plaque at Risk (PARISK) Study

Introduction: Ischemic stroke incidence varies significantly with respect to sex and cardiovascular risk factors (CVRF), a relationship that it is not well understood. Calcification in carotid atherosclerosis is known to impact plaque stability, potentially linked to ischemic stroke. The aim of this study was to assess the in-depth calcification morphometrics within extracranial carotid atherosclerosis, their temporal changes, and associations with sex and CVRF.
Methods: Carotid arteries (n=144) with confirmed atherosclerosis and mild-to-moderate stenosis from 72 symptomatic patients (Plaque-At-Risk study) with recent ischemic event due to ischemia in the territory of a carotid artery were imaged using multi-detector computed tomography angiography (MDCTA) at baseline and after 2 years. The lumen, vessel wall, and calcifications were segmented semi-automatically and the carotid geometries were 3D reconstructed. A comprehensive morphometric assessment of carotid calcifications was performed on the baseline and follow-up scans. We investigated distributions of these metrics and their associations with sex and CVRF using Generalized Linear Mixed Models.
Results: Our findings suggest that women have larger (4.5 mm2 (95%CI: 3.2-6.2) vs 3.2 mm2 (95%CI: 2.4-4.2)) calcifications, located closer to the lumen (0.6 mm (95%CI: 0.4-0.8) vs 0.9 mm (95%CI: 0.7-1.2)) compared to men at baseline and follow-up, adjusted for baseline measurements. At the baseline, non-smokers had larger (5.3 mm2 (95%CI: 3.7-7.5) vs 3.2 mm2 (95%CI: 2.3-4.4)), and longer (5.7 mm (95%CI: 4.1-7.3) vs 2.4 mm (95%CI: 1.6-3.6)) calcifications than the current smokers. Diabetic patients had thicker (1.1 mm (95%CI: 0.8-1.3) vs. 0.8 mm (95%CI: 0.7-0.9)) carotid calcifications at baseline.
Conclusion: Our in-depth analyses exposed several geometric features of carotid calcifications associated with sex and CVRF, and provided further insight into the pathophysiology of carotid atherosclerosis.