A multiscale approach for determining the morphology of endothelial cells at a coronary artery

Abstract

The morphology of endothelial cells (ECs) may be an indication for determining atheroprone sites. Until now, there has been no clinical imaging technique to visualize the morphology of ECs in the arteries. The present study introduces a computational technique for determining the morphology of ECs. This technique is a multiscale simulation consisting of the artery scale and the cell scale. The artery scale is a fluid-structure interaction simulation. The input for the artery scale is the geometry of the coronary artery, that is, the dynamic curvature of the artery due to the cardiac motion, blood flow, blood pressure, heart rate, and the mechanical properties of the blood and the arterial wall, the measurements of which can be obtained for a specific patient. The results of the artery scale are wall shear stress (WSS) and cyclic strains as the mechanical stimuli of ECs. The cell scale is an inventive mass-and-spring model that is able to determine the morphological response of ECs to any combination of mechanical stimuli. The results of the multiscale simulation show the morphology of ECs at different locations of the coronary artery. The results indicate that the atheroprone sites have at least 1 of 3 factors: low time-averaged WSS, high angle of WSS, and high longitudinal strain. The most probable sites for atherosclerosis are located at the bifurcation region and lie on the myocardial side of the artery. The results also indicated that a higher dynamic curvature is a negative factor and a higher pulse pressure is a positive factor for protection against atherosclerosis.

Numerical study of the effect of hemodynamic variables on LDL concentration through the single layer of the Left Anterior Descending coronary artery (LAD) under the heart pulse

“…These results have been extracted for the case that the artery has no movement and the inlet is non-physiological and they describe that the reductive trend of shear stress along the flow direction would be intensified. The results are in good agreement with biological studies of Samady et al 31 and numerical simulation results of Prosi et al 6 and Pakravan et al 8 Local reduction of shear stress on the wall is the most well-known factor of diffusing LDL into the wall and emerging atherosclerosis. 31 Therefore, the region after bifurcation is a potential area for artery stenosis.…”

“…The artery wall is assumed as porous media. The fluids flow in porous media (unlike non-porous media that follow the poiseuille law) follows Darcy law according to equation (8).…”

“…Their results showed that minimum shear stress would take place on the myocardial wall. Pakravan et al 8 have also compared two-way solution cases of fluid and wall to those of each separately for bifurcations of LMA, LCX and LAD together with considering the influences of the wall. Zhang et al 9 studied the entropy analysis of the blood flow through an anisotropically tapered artery under the suspension of magnetic Zinc-oxide (ZnO) nanoparticles (NPs).…”

Long-term prognostic impact of paravalvular leakage on coronary artery disease requires patient-specific quantification of hemodynamics

“…However, since: (1) patient-specific boundary conditions were not used; (2) hemodynamic validation was not performed; and (3) coronary arteries were excluded from the computational domain, the models developed in these studies did not satisfy the three requirements outlined in the Introduction 67 – 69 , 131 – 133 . In addition, several studies have recently used FSI as a promising tool for coronary arteries exclusively, since it allows consideration of the interactions of artery wall elastic behavior and blood flow mechanics, thus demonstrating its worth as a more realistic tool for numerical modelling of coronary arteries 58 , 134 – 141 . While only a few numbers of these studies 58 coupled lumped parameter model-based boundary conditions with FSI modelling, the lumped-parameter models were not patient-specific.…”

High precision invasive FFR, low‐cost invasive iFR, or non‐invasive CFR?: optimum assessment of coronary artery stenosis based on the patient‐specific computational models

“…CFD methods not only eliminate some side effects of the clinical examinations but also help to evaluate the results of clinical tests numerically. Consequently, CFD can provide researchers with valuable insights about some controversial clinical hypotheses 21‐25 . In addition, CFD methods can calculate local hemodynamic parameters, such as time‐averaged wall shear stress (TAWSS), oscillatory shear index (OSI), and relative residence time (RRT), which are not clinically measurable.…”