The influence of hematocrit on the hemodynamics of artificial heart valve using fluid-structure interaction analysis

Patients with severe aortic stenosis could regain the proper hemodynamic performance and cardiovascular output by restoring the diseased aortic valve with an artificial heart valve replacement. However, given the uniqueness of each patient, the hemodynamic improvements after an aortic valve replacement could vary. The biomechanical and hemodynamical parameters can be influenced by some major factors including the patient's blood pressure and hematocrit. Therefore, the objective of this study is to analyze the hemodynamics and valve mechanics of a bileaflet mechanical heart valve and investigate the hemorheological characteristics under the change of hematocrit. The fully coupled fluid-structure interaction (FSI) approach was used to model the hemodynamics and valve dynamics. Particle image velocimetry (PIV) experiments were conducted with in vitro benchtop model using ViVitro Pulse Duplicator to verify and validate the FSI models. The current numerical analysis revealed the hematocrit influenced the shear stress distributions over a cardiac cycle. The structural stresses in the mechanical valve were also affected by the distributions of the shear stress in the blood flow. Parameter dependencies found in the current study indicate that the hematocrit is influential when conducting patient-specific modelling of prosthetic heart valves.