Carotid Plaque Lipid Content and Fibrous Cap Status Predict Systemic CV Outcomes: The MRI Substudy in AIM-HIGH

Area of Science:

• Cardiovascular Imaging
• Atherosclerosis Research
• Biomarker Discovery

Background:

• Advancements in atherosclerosis imaging enable detailed plaque characteristic assessment.
• Certain plaque features correlate more directly with acute cardiovascular event pathogenesis than plaque burden alone.

Purpose of the Study:

• To determine if carotid plaque characteristics predict systemic cardiovascular outcomes.
• To identify specific plaque features associated with adverse events in patients with established atherosclerotic disease.

Main Methods:

• Carotid magnetic resonance imaging (MRI) was used to assess plaque composition and high-risk features in patients from the AIM-HIGH trial.
• Prospective associations between MRI measurements and cardiovascular endpoints were analyzed using Cox proportional hazards models.

Main Results:

• High lipid content (HR: 1.57; p=0.002) and thin/ruptured fibrous cap (HR: 4.31; p=0.003) in carotid plaques strongly predicted cardiovascular outcomes.
• Intraplaque hemorrhage showed marginal association (HR: 3.00; p=0.053), while calcification and plaque burden did not significantly predict events.
• Associations remained significant after adjusting for clinical risk factors and treatment assignment.

Conclusions:

• Carotid plaque lipid content and fibrous cap status are strong predictors of systemic cardiovascular outcomes in patients with established atherosclerotic disease.
• Plaque vulnerability markers identified via MRI may function as novel surrogate markers for systemic atherothrombotic risk.