Atheroprone sites of coronary artery bifurcation: Effect of heart motion on hemodynamics-dependent monocytes deposition

Abstract

Atherosclerosis as a common cardiovascular disease is a result of both adverse hemodynamics conditions and monocyte deposition within coronary arteries. It is known that the adhesion of monocytes on the arterial wall and their interaction with the vascular surface are one of the main parameters in the initiation and progression of atherosclerosis. In this work, hemodynamic parameters and monocyte deposition have been investigated in a 3D computational model of the Left Anterior Descending coronary artery (LAD) and its first diagonal branch (D1) under the heart motion. A one-way Lagrangian approach is performed to trace the monocyte particles under different blood flow regimes and heart motion conditions. The hemodynamic results show that the myocardial wall, and also the flow divider wall can be candidates for atheroprone sites. The dynamic movement and pulsatile inlet changed the flow rate between branches about 21% compared to the static case and steady inlet. On the other hand, the calculation of monocytes' depositional behavior illustrates that they settle down downstream the LAD-D1 bifurcation and on the myocardial wall. The deposition rate is closely associated with the inlet type and changing the steady inlet to the sinusoidal and real physiologic profile showed a 150% increase in the deposition rate. These results ensure that the myocardial wall and LAD-D1 bifurcation are the desirable locations for atherosclerosis. These results are in good agreement with the clinical observations.

Keywords: Atherosclerosis; Coronary artery diseases; Lagrangian approach; Monocytes; Wall shear stress.