3039Vulnerability of carotid atherosclerosis: relationship with plaque location, plaque eccentricity and vessel remodeling patterns. Insight from the the MAGNETIC observational study

Abstract

Carotid atherosclerosis is a cause of brain ischemic events. Cardiovascular magnetic resonance (CMR) can assess plaque vulnerability. We investigated atherosclerosis vulnerability in relation to plaque location, eccentricity and vessel remodeling. Methods-Baseline CMR evaluations of the MAGNETIC observational study, were analyzed. We quantitated with MRI-Plaque View™, vessel lumen/wall and vulnerable plaque components of a 32-mm segment of common carotid artery (12 mm), bulb (8 mm) and internal carotid artery (12 mm). Lipid-rich necrotic core [LRNC], fibrous cap [CAP] and intraplaque hemorrhage [IPH] were expressed as percent of wall area. Results-A data-set of 8080 sections of adequate quality in 260 patients (198 male [76%], median age 71 years [65–76]), were analyzed. Patients were on therapy with antiplatelet, ACE-inhibitors/ARB and statins (196–229 out of 260 [75–88%]). We found significant differences in plaque composition according to longitudinal and circumferential location, eccentricity and vessel remodeling (table). At multivariate regression analysis, including classical RF and atherosclerotic burden, we found an independent association of: LRNC and IPH with longitudinal location, eccentricity and positive remodeling, and of CAP with eccentricity (p<0.001 for all). Lipid-rich necrotic core Fibrous cap Intraplaque hemorrhage Longitudinal distribution Common carotid artery 4% [1–10] p<0.001 6% [4–11] p<0.001 0% [0–3] p<0.001 Carotid bulb 7% [3–13] 9% [5–13] 1% [0–4] Internal carotid artery 3% [0–10] 7% [4–11] 0% [0–1] Circunferenzial location Antero-medial 4% [0–11] p<0.001 7% [4–12] p=0.07 0% [0–2] p<0.001 Antero-lateral 6% [1–12] 8% [5–12] 1% [0–4] Postero-lateral 5% [0–11] 7% [4–12] 0% [0–3] Postero-medial 5% [0–11] 7% [4–12] 0% [0–1] Plaque eccentricity Concentric 3% [0–9] p<0.001 7% [4–11] p<0.001 0% [0–2] p<0.001 Eccentric 9% [4–15] 9% [5–13] 1% [0–4] Remodelling pattern Negative 4% [0–10] p<0.001 7% [4–11] p<0.001 0% [0–2] p<0.001 Positive 7% [3–13] 8% [5–13] 1% [0–4] Plaque eccentricity was defined as eccentricity index (EI = [maximum wall thickness − minimum wall thickness]/maximum wall thickness) in the highest quartile. Positive remodeling was defined as remodeling index (= [vessel cross-sectional area − reference area]/cross-sectional area) in the highest quartile. Conclusions Carotid atherosclerotic plaque vulnerability seems to be independently associated with longitudinal location, plaque eccentricity and vessel positive remodeling. Acknowledgement/Funding Bayer AG, Leverkusen, Germany

State-of-the-art CT and MR imaging and assessment of atherosclerotic carotid artery disease: standardization of scanning protocols and measurements—a consensus document by the European Society of Cardiovascular Radiology (ESCR)

“…6). The eccentricity increases the biomechanical stress to the plaque by determining an increased vulnerability [108] and it was found that it is associated with an increased prevalence of IPH [109]. Initially, positive remodeling was believed to be a protective phenomenon [110], but newer pieces of evidence have demonstrated that it should be considered a parameter of vulnerability [111].…”