Effects of Stenosis Shape and Severity on Hemodynamics of Patient-Specific Coronary Arteries: A Numerical Study*

Atherosclerosis causes plaque buildup in arterial walls, occludes the lumen region, and hinders organ functioning with inadequate supply of vitals such as nutrients and oxygen. Plaques comprising lipids are vulnerable to rupture when acted upon by perturbed hemodynamic forces. Clinical assessments of coronary arterial diseases have shown active rupture-prone sites on proximal stenotic regions and close to the throat. Stenosis severity is a salient feature of clinical interventions for treating coronary artery diseases. However, stenotic shapes with a steep proximal slope intensify hemodynamic stresses and contribute to plaque rupture, which requires thorough analysis. Computational Fluid Dynamics (CFD) simulations are performed to investigate the effect of proximal shape and sequential stenoses on reconstructed patient-specific coronary arteries. Stenosis shapes are quantified using gradients of arterial lumen along the proximal region. Further, physiological flow conditions such as baseline rest and exercise are integrated to analyse flow features, hemodynamics and pressure gradient across the stenosis. This study addresses the significance of stenosis shape, emphasizing the proximal region and severity for assessing hemodynamics in patient-specific coronary arteries.