Fluid-structure interaction simulation of calcified aortic valve stenosis.

Area of Science:

• Cardiovascular Mechanics
• Biomedical Engineering
• Computational Fluid Dynamics

Background:

• Calcified aortic valve stenosis (CAVS) is a prevalent cardiovascular disease.
• Calcium buildup and tissue thickening impede blood flow from the left ventricle to the aorta.
• Understanding the mechanics of calcified aortic valves (AV) is crucial.

Purpose of the Study:

• To investigate the dynamic and hemodynamic effects of calcification on the aortic valve.
• To develop a computational model of CAVS using a hybrid immersed boundary/finite element method.
• To analyze the impact of calcification on AV leaflet mechanics, blood flow, and ventricular performance.

Main Methods:

• Utilized a hybrid immersed boundary/finite element (IB/FE) method.
• Developed a computational CAVS model by differentiating calcified and healthy regions in AV leaflets with distinct constitutive equations.
• Simulated AV dynamics and hemodynamics under normal and calcified conditions.

Main Results:

• Calcification significantly reduces AV leaflet elasticity and mobility, leading to a smaller opening area and altered blood flow patterns.
• Calcified valves exhibit increased local stress and strain.
• AV stenosis increases left ventricular energy loss and transvalvular pressure gradients, consistent with clinical risk stratification.

Conclusions:

• Computational models of CAVS provide valuable insights into AV stenosis-induced ventricular dysfunction.
• These models have potential for aiding in the computational engineering-assisted diagnosis of AV diseases.
• The study highlights the significant mechanical and hemodynamic alterations caused by aortic valve calcification.