Plaque phenotypes across remodeling patterns in vertebrobasilar atherosclerosis: a high-resolution magnetic resonance vessel wall imaging study.

Background: Intracranial atherosclerosis is the predominant etiology of ischemic stroke in East Asian populations. Atherosclerotic progression frequently involves concomitant vascular remodeling, and stroke risk profiles may vary across distinct vascular remodeling morphologies. However, the intracranial vertebrobasilar plaque features of different remodeling patterns have not been extensively characterized. In this study, high-resolution magnetic resonance vessel wall imaging (HR-MRI) was used to identify vertebrobasilar plaque phenotypes across different remodeling patterns in order to generate deeper insights into the mechanisms of ischemic stroke in this population. Methods: From January 2020 to July 2021, 208 patients with posterior circulation atherosclerosis were retrospectively evaluated. Demographic data, atherosclerosis risk factors, blood glucose and lipid profiles, homocysteine level, and imaging data were collected. The characteristics of vascular plaques were analyzed via HR-MRI. Parameters including vascular remodeling index (RI), degree of stenosis, plaque burden, plaque enhancement, surface morphology, distribution pattern, and plaque location were recorded. A RI value ≤0.95 indicated negative remodeling (NR), ≥1.05 indicated positive remodeling (PR), and a value between 0.95 and 1.05 indicated intermediate remodeling (IR). Comparative analyses assessed differences in demographics, risk factors, laboratory indices, and plaque features across remodeling groups. Subsequently, stratification into positive and non-PR cohorts was followed by univariate and multivariate logistic regression to identify risk factors for stroke. Predictive performance was evaluated through receiver operating characteristic (ROC) curve analysis. Results: The cohort comprised 133 cases of PR (63.9%), 35 cases of IR (16.8%), and 40 cases of NR (19.2%), indicating a predominance of PR in intracranial vertebrobasilar atherosclerosis. Degree of vascular stenosis, plaque burden, and distribution patterns were associated with vascular remodeling type (P<0.001, P<0.001, and P=0.008, respectively). However, no significant association was found between plaque enhancement and remodeling patterns. The multivariate analysis revealed that the independent risk factors for stroke in the non-PR group were plaque enhancement [adjusted odds ratio (aOR) 6.01; 95% confidence interval (CI): 1.48-24.38; P=0.012] and plaque location in the basilar artery (aOR: 5.41; 95% CI: 1.21-24.19; P=0.027); the area under the ROC curve (AUC) of the combined model was 0.802 (95% CI: 0.698-0.907). In the PR group, the independent risk factors for stroke were plaque enhancement (aOR 6.93; 95% CI: 2.5-19.19; P<0.001), diffuse distribution (aOR 3.3; 95% CI: 1.12-9.77; P=0.031), and irregular surface morphology (aOR 3.7; 95% CI: 1.7-11.7; P=0.026); the AUC of the combined model was 0.812 (95% CI: 0.729-0.896). Notably, stenosis severity and plaque burden were not independently associated with stroke risk in either group (P>0.05). Conclusions: Our study established remodeling pattern-specific stroke risk profiles in intracranial vertebrobasilar atherosclerosis. Marked plaque enhancement consistently predicted stroke across remodeling subtypes. Plaque enhancement assessment should be prioritized regardless of remodeling phenotype, and different preventive strategies may be needed depending on the remodeling classification.