Valve stiffness and aortic hemodynamics: insights from fluid-structure interaction simulations

This study investigates how aortic valve leaflet stiffness affects hemodynamics and structural performance using high-fidelity fluid–structure interaction simulations of a patient-specific aortic arch. Three leaflet materials were analyzed (Young’s moduli: 10, 25, and 50 MPa). The most compliant model (10 MPa) exhibited the largest systolic deformation (≈ 5.0 mm), physiological flow patterns, and the lowest wall shear stress (WSS) near the valve (≈ 4 Pa), but also generated the highest peak von Mises stress (> 2.0 MPa) and complex vortex structures. In contrast, the stiffest model (50 MPa) showed minimal deformation (< 0.5 mm), reduced leaflet stress (< 0.5 MPa), but induced locally WSS (> 50 Pa) along the aortic arch. Despite these local variations, the area-averaged WSS profiles remained similar across all models (15.8 Pa for 10 MPa vs. 14.3 Pa for 50 MPa). These results reveal a trade-off: compliant valves closely mimic native motion but experience higher mechanical stress, while stiffer valves lower leaflet stress but increase vascular shear loading. These insights are critical for optimizing material selection in artificial valve design.