The Relation between Atherosclerosis Plaque Composition and Plaque Rupture

Area of Science:

• Cardiovascular biomechanics
• Biomedical engineering
• Pathology of atherosclerosis

Background:

• Arterial layers (intima, media, adventitia) have distinct structures and mechanical properties.
• Damage to the intima initiates the inflammatory response leading to atherosclerosis plaque formation.
• Plaque composition (smooth muscle cells, calcium) and geometry evolve over time, influencing mechanical stress.

Purpose of the Study:

• To investigate the biomechanical stresses on atherosclerotic plaques.
• To determine how plaque characteristics affect vulnerability to rupture.
• To analyze the influence of fibrous cap thickness, lipid core size, and calcification on plaque stress.

Main Methods:

• Coronary artery was modeled using ANSYS software.
• Fibrous cap thickness was varied from 40 μm to 250 μm.
• Lipid pool percentage was increased from 10% to 90%.
• Calcium was modeled in both agglomerated and microcalcium forms to assess its impact.

Main Results:

• Plaque stress decreases exponentially with increasing fibrous cap thickness.
• Larger lipid pools correlate with increased plaque vulnerability.
• Calcified plaques generally exhibit higher maximum stress compared to non-calcified plaques.

Conclusions:

• Plaque stress is influenced by the location of calcium deposits (near or far from the lumen).
• Increased calcium deposition in plaques reduces maximum stress, regardless of its form or location.
• Understanding these biomechanical factors is crucial for predicting plaque rupture risk.