# Composition of Carotid Plaques Differs Between Chinese and United States Patients: A Histology Study

## TL;DR

Carotid plaques from Chinese patients have different histological features compared to those from U.S. patients, suggesting distinct pathophysiology in atherosclerosis.

## Contribution

This study provides the first detailed histological comparison of carotid plaques between Chinese and U.S. populations.

## Key findings

- Chinese plaques had more lipid pools and recent intraplaque hemorrhage compared to U.S. plaques.
- Chinese plaques were more homogeneous and showed more xanthoma features than U.S. plaques.

## Abstract

The clinical manifestations of cerebrovascular disease are known to differ between the Chinese and United States (U.S.) populations as do the plaque features on imaging.

The aim of this study was to investigate and compare the histological features of excised carotid plaques from Chinese and U.S. patients.

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.

A total of 1,152 histological sections from 75 Chinese patients and 1,843 sections from 111 U.S. 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 U.S. group. After adjusting for confounding factors, carotid plaques in the Chinese population were more likely to have more 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%), and 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 U.S. plaques (20% vs 2.7%, p<0.001).

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 could enhance the gap in racial pathology comparison, indicating a need for a different management approach.