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

Mishal Raza-Taimuri1, Ian Y Chen2, Hamid Sadat3

  • 1Department of Mechanical Engineering, University of North Texas, Denton, TX, USA.

Insights

Non-uniform calcification in aortic valves significantly alters blood flow and mechanics. Current diagnostic methods struggle to predict calcification severity, with only effective orifice area and maximum opening ratio proving reliable.

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.
Abstract