Composition of carotid plaques differs between Chinese and US patients: a histology study

Background: The clinical manifestations of cerebrovascular disease are known to differ between the Chinese and United States (US) populations as do the plaque features on imaging. Objectives: The aim of this study was to investigate and compare the histological features of excised carotid plaques from Chinese and US patients. Methods: Carotid endarterectomy specimens collected from two prospective studies were included. The entire plaque was serially sectioned (10-µm thickness) at 0.5–1 mm intervals. Hematoxylin and eosin staining and Mallory’s trichrome staining were performed. The morphology and components of the plaques were measured and compared between the two groups. Results: A total of 1152 histological sections from 75 Chinese patients and 1843 sections from 111 US patients were analyzed. The Chinese group had significantly smaller minimum lumen diameters (median: 1.1 vs. 1.3 mm, p = 0.046) and a larger percent wall volume (median: 74% vs. 70%, p = 0.018) than the US group. After adjusting for confounding factors, carotid plaques in the Chinese population had larger lipid pools (β = 10.0%, 95% CI: 4.9 to 15.9%), more recent intraplaque hemorrhage (IPH; β = 8.4%, 95% CI: 4.5 to 12.7%), less late IPH (β = − 8.2%, 95% CI: − 11.3 to − 5.4), and fewer fibrous cap disruptions (45% vs. 67%, p = 0.061). Chinese plaques were more homogeneous and had a higher percentage of plaques with features of xanthomas than did US plaques (20% vs 2.7%, p < 0.001). Conclusions: The histology of Chinese plaques differs significantly from that of U.S. plaques, suggesting substantial differences in the pathophysiology of atherosclerotic cerebrovascular disease between Chinese and North American populations, which indicates a need for a different management approach.