Hemodynamic Analysis of Non-uniformly Calcified Aortic Valve Using a Partitioned Fluid-Structure Interaction...

Area of Science:

• Cardiovascular Research
• Biomedical Engineering
• Computational Fluid Dynamics

Background:

• Calcific Aortic Valve Disease (CAVD) involves progressive aortic valve calcification, leading to stenosis and impaired cardiac function.
• Existing Computational Fluid Dynamics (CFD) studies often assume uniform calcification, which doesn't reflect clinical reality.
• Current diagnostic techniques may not accurately assess the impact of non-uniform calcification.

Purpose of the Study:

• To extend CFD simulations to model non-uniformly calcified aortic valves.
• To evaluate the diagnostic accuracy of clinical methods under non-uniform calcification conditions.

Main Methods:

• High-fidelity fluid-structure interaction (FSI) simulations were performed.
• A patient-specific valve model from CT images was used.
• Non-uniform calcification was simulated by varying leaflet elasticity across different severity levels.

Main Results:

• Non-uniform calcification increased maximum jet velocity (35-50%) and transvalvular pressure gradient (150-170%).
• Significant changes in vortex shedding, flow separation, and wall shear stress fluctuations were observed.
• Effective orifice area (EOA) and maximum opening ratio (MOR) were identified as reliable predictors of calcification severity.

Conclusions:

• Non-uniform calcification profoundly impacts aortic valve hemodynamics and leaflet mechanics.
• Increased calcification severity leads to significant alterations in flow patterns and biomechanical responses.
• The study underscores the need for improved diagnostic tools for better CAVD management.