Linking Carotid Plaque Immune Subtypes to Multimodal Ultrasound Features

Area of Science:

• Cardiovascular Research
• Immunology
• Medical Imaging

Background:

• Carotid plaque instability is a major cause of stroke.
• Accurate identification of high-risk plaques is crucial for timely intervention.
• Current methods for plaque characterization have limitations.

Purpose of the Study:

• To establish a plaque immune microenvironment classification system.
• To explore the utility of multimodal ultrasound in non-invasively identifying high-risk plaque subtypes.
• To investigate the association between principal component analysis (PCA)-derived immune subtypes and ultrasound features.

Main Methods:

• Prospective study of 50 patients undergoing carotid endarterectomy (CEA).
• Immunohistochemistry (IHC) assessed seven markers (IL-6, TNF-α, IFN-γ, IL-2, CD11b, MPO, MVD).
• Principal component analysis (PCA) and hierarchical clustering defined immune subtypes; ultrasound evaluated plaque vulnerability and neovascularization.

Main Results:

• Four PCA-defined plaque subtypes identified: inflammation-dominated, angiogenesis-dominated, high inflammation/angiogenesis, and stable.
• The high inflammation/angiogenesis subtype (Type III) exhibited the highest inflammatory factors and microvessel density (MVD), with a high rate of recent ischemic events.
• Ultrasound vulnerability score and intraplaque neovascularization (IPN) grade correlated significantly with inflammatory markers and MVD, respectively.

Conclusions:

• Principal component analysis (PCA)-based immune subtyping of carotid plaques is feasible.
• Multimodal ultrasound, specifically vulnerability score and IPN grade, shows potential for non-invasively identifying high-risk plaque subtypes.
• This approach may offer a novel imaging strategy for carotid plaque risk stratification.