Numerical modeling of the flow in stenosed coronary artery. The relationship between main hemodynamic parameters.

The severity of coronary arterial stenosis is usually measured by either simple geometrical parameters, such as percent diameter stenosis, or hemodynamically based parameters, such as the fractional flow reserve (FFR) or coronary flow reserve (CFR). The present study aimed to establish a relationship between actual hemodynamic conditions and the parameters that define stenosis severity in the clinical setting. We used a computational model of the blood flow in a vessel with a blunt stenosis and an autoregulated vascular bed to simulate a stenosed blood vessel. A key point in creating realistic simulations is to properly model arterial autoregulation. A constant flow regulation mechanism resulted in CFR and FFR values that were within the physiological range, while a constant wall-shear stress model yielded unrealistic values. The simulation tools developed in the present study may be useful in the clinical assessment of single and multiple stenoses by means of minimally invasive methods.