Computational analysis of stenosis geometry effects on right coronary hemodynamics.

Coronary artery disease (CAD) is one of the most frequent causes of death in western countries. It is characterized by the presence of coronary artery stenosis that can be flow-limiting or susceptible to rupture, triggering intracoronary thrombosis and -consequently- an acute myocardial infarction. For these reasons, hemodynamic alterations associated to the presence of coronary stenosis are of large relevance. Aim of this study was to numerically investigate the effect of stenosis geometry on hemodynamics, comparing three different shapes with an equivalent stenotic lumen. A right coronary artery (RCA) was reconstructed from the angiogram of a patient. Flow pattern analyses were performed using the computational fluid dynamic (CFD) approach, showing that the worst stenosis geometry is the elliptical one, characterized by areas with stasis, multidirectional velocity and high wall shear stress (WSS). On the other hand, the least dangerous stenosis is the parabolic one. However, the strongest predictor of pressure drop is not geometry but the minimal lumen area. In conclusion, while the minimal lumen area is associated to the trans-stenotic pressure drop, stenosis geometry has a significant impact on translesional flow pattern and WSS.