Mechanical properties of model atherosclerotic lesion lipid pools

Abstract

Structural analysis of atherosclerotic coronary arteries has suggested that stress concentrations are associated with plaque rupture and that these stress concentrations are critically dependent on the geometry and mechanical properties of the fibrous cap and lipid pool. Recent clinical trials of lipid-lowering therapy have shown a significant reduction in cardiac events associated with plaque rupture perhaps because of the changing composition of subintimal lipid pools. To test the hypothesis that changes in lipid composition can change the mechanical properties of lipid pools, we measured the dynamic shear moduli of combinations of cholesterol monohydrate crystals, phospholipids, and triglycerides similar to those found in atherosclerotic lesions. Increasing the cholesterol monohydrate concentration from 0% to 50% increased the real component of the dynamic shear modulus (storage modulus or stiffness) by 4.5 times at a frequency of 1 Hz (P