Abstract
OBJECTIVE: To compare the morphological and compositional characteristics of carotid plaques in two cohorts (2002-2005 and 2012-2015) of Chinese patients using magnetic resonance vessel wall imaging. METHODS: Symptomatic patients with carotid atherosclerotic plaques who underwent carotid vessel wall magnetic resonance imaging between 2002-2005 and 2012-2015 were retrospectively recruited. Plaque morphology [including mean wall area, wall thickness, and maximum normalized wall index (NWI)] and composition [including calcification, intraplaque hemorrhage, and lipid-rich necrotic core (LRNC)] in symptomatic carotid arteries were evaluated and compared between patients in these two time periods. RESULTS: A total of 258 patients, including 129 patients in the 2002-2005 cohort and 129 patients in the 2012-2015 cohort, were recruited. Statin use (49.6%vs. 32.6%, P = 0.004) and hypertension (76.0% vs. 62.8%, P = 0.015) were significantly more common in the 2012-2015 cohort than in the 2002-2005 cohort. Patients in the 2012-2015 cohort also exhibited significantly low plaque burden parameters (allP < 0.05), as well as a lower prevalence (68.2% vs. 89.9%, P < 0.001) and volume percentages of LRNC (11.2% ± 14.2% vs. 25.7% ± 17.7%, P < 0.001). These differences remained significant after adjustment for clinical factors. The differences in the volume percentages of LRNC also remained significant after an additional adjustment for maximum NWI ( P < 0.001). CONCLUSIONS: Patients in the 2012-2015 cohort had a lower plaque burden and volume percentages of LRNC in symptomatic carotid arteries than those in the 2002-2005 cohort. These findings indicate that carotid plaques in the recent cohort had a lower severity and vulnerability.