Fluid-structure interaction (FSI) simulations were conducted in patient-specific coronary vulnerable plaque (VP) geometries reconstructed from Micro-CT and intravascular ultrasound (IVUS), in order to study the effects of microcalcification (micro-Ca), anisotropic vessel properties, and hypertension on plaque vulnerability.
The models reconstructed from IVUS included vessel wall, fibrous cap, lipid core and large calcifications. A model reconstructed post mortem from a coronary specimen of a patient with confirmed VP was scanned using high resolution micro-CT. This enabled capture of micro calcifications embedded in the VP fibrous cap in addition to the plaque components mentioned above. Regions susceptible to tissue failure were studied. The thin fibrous cap regions of the plaque were characterized by high stress concentrations. The presence of single or multiple micro-calcified spots embedded within the fibrous cap was studied as well. Micro-Ca significantly enhanced stresses within the fibrous cap, significantly contributing to the risk of rupture.