# Hemodynamic Alteration in Aortic Valve Stenosis: CFD Insights from Leaflet-Resolved Models

## TL;DR

This paper uses computational models to study how aortic valve stenosis affects blood flow and stresses in the aorta, showing how severity impacts hemodynamics.

## Contribution

The study introduces leaflet-resolved CFD models to analyze hemodynamic changes across different stenosis severities, revealing non-linear flow patterns and mechanical stresses.

## Key findings

- Velocity and wall shear stress increase non-linearly with stenosis severity, reaching peak values of 4.7 m/s and 122 Pa in severe cases.
- Severe stenosis causes an eccentric jet, increased turbulence, and expanded recirculation zones in the aortic arch.
- Helicity and pressure loss coefficient significantly rise with higher stenosis severity, indicating complex flow patterns.

## Abstract

Aortic valve stenosis, is a prevalent cardiovascular disease, narrows the valve orifice and restricts blood flow, resulting in abnormal high velocities and shear stresses. The progression of these hemodynamic abnormalities and their link with stenosis severity remain incompletely understood, which are critical for early detection and intervention. Computational Fluid Dynamics (CFD) was employed to characterize aortic hemodynamics across healthy, mild, moderate, and severe stenosis using a 3D steady-state model with idealized leaflet geometries. Key flow parameters, including velocity distribution, wall shear stress (WSS), pressure loss coefficient, and helicity, were evaluated. Results show a non-linear increase in velocity and WSS with stenosis severity, with peak jet velocities of 1.08, 1.82, 2.73, and 4.7 m/s and peak WSS of 11, 35, 80, and 122 Pa at the aortic arch, respectively. Severe stenosis produced a highly eccentric jet along the anterior of aortic arch, accompanied by a narrower jet, increased turbulence intensity and expanded recirculation zones. A significant increase in helicity and pressure loss coefficient was also observed for higher stenosis severities. These findings highlight the influence of valve leaflets on aortic flow dynamics, providing physiologically relevant insights into stenosis-induced mechanical stresses that may drive endothelial dysfunction and support earlier detection of disease progression.