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 Study

INTRODUCTION: Ischemic stroke incidence varies significantly with respect to sex and cardiovascular risk factors (CVRFs), a relationship that it is not well understood. Calcification in carotid atherosclerosis is known to impact plaque stability, potentially linked to ischemic stroke. The objective was to assess the in-depth calcification morphometrics within extracranial carotid atherosclerosis, their temporal changes, and associations with sex and CVRFs. 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 multidetector computed tomography angiography (MDCTA) at baseline and after 2 years. The lumen, vessel wall, and calcifications were segmented semiautomatically, 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 CVRFs 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]) in contrast to men at baseline and follow-up, adjusted for baseline measurements. At the baseline, nonsmokers 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 CVRFs and provided further insight into the pathophysiology of carotid atherosclerosis.