Introduction: Atherosclerosis of the extracranial carotid and intracranial arteries is an important contributor to stroke. Autopsy studies suggest that the location and components of atheroma may vary between different ethnic groups. Advances in cerebrovascular vessel wall imaging with 3D-magnetic resonance imaging (MRI) have provided a critical tool to assess these differences in vivo.
Hypothesis: We tested the hypothesis that carotid culprit plaques are more common in U.S. patients, and that intracranial culprit plaques are more common in Chinese patients.
Methods: As part of the ongoing Culprit Plaque in Acute Cerebral Infarction study, patients with acute anterior circulation ischemic stroke were recruited at the University of Washington and the Beijing Tiantan Hospital. Plaque presence, location, and composition (intraplaque hemorrhage [IPH], lipid core, calcification, disrupted luminal surface [DLS]) in the carotid and intracranial arteries on the symptomatic side were evaluated using a 3D multi-contrast vessel wall MRI protocol. Carotid and intracranial arteries were reviewed independently by an experienced reader blinded to clinical characteristics and ethnic group.
Results: Twenty patients from the U.S. (median age: 59 years; 65% male) and 26 patients from China (58 years; 69% male) were evaluated. Of those, 18 U.S. patients (90%) and 20 Chinese patients (77%) had at least one plaque in either the carotid or intracranial arteries (p=0.4). Of those with plaque, 17 U.S. (94%) and 12 Chinese (60%) patients had carotid artery plaques (p= 0.02), and 11 U.S. (61%) and 19 Chinese (95%) patients had intracranial artery plaques (p=0.02). Features of possible culprit plaque (IPH and/or DLS) in the carotid artery were found in 8 U.S. patients (47%) but only 1 Chinese patient (8%) (p=0.04). Plaque composition in intracranial arteries was not significantly different between the two groups.
Conclusion: Possible culprit plaques in the carotid artery were more common in symptomatic U.S. patients than Chinese patients, while intracranial plaques were more common in the Chinese patients. Accurate localization of the culprit plaque has important implications for treatment.