Fluid–structure interaction of calcified native aortic valves using SPH

Cardiovascular diseases remain a major global health burden, with calcific aortic valve disease (CAVD) constituting one of the most prevalent and debilitating conditions. Progressive leaflet stiffening due to calcific deposition alters valve kinematics, disrupts haemodynamics, and increases the risk of adverse events. Numerical modelling has emerged as a powerful tool for investigating these mechanisms, particularly for estimating quantities such as wall shear stress that are difficult to measure in vivo. However, traditional Eulerian-based fluid–structure interaction (FSI) methods rely on dynamic mesh deformation and remeshing, which can compromise numerical stability and accuracy when simulating the large deformations characteristic of calcified valves. The presents study proposes a fully coupled FSI framework for a native aortic valve using a purely Smoothed Particle Hydrodynamics (SPH) approach. The Lagrangian formulation of SPH eliminates mesh-related constraints, enabling robust representation distorted leaflet geometries and their interaction with pulsatile blood flow. Three calcification scenarios — healthy, moderately calcified, and partially calcified—are analysed to quantify their influence on valve dynamics and downstream haemodynamics. The model captures key pathological features, including asymmetric valve opening, altered leaflet motion, and the emergence of high-shear recirculating regions associated with thrombogenic risk. Quantitative comparisons with echocardiographic measurements and established finite-volume simulations demonstrate strong agreement, validating the predictive capability of the framework. Overall, the findings highlight the potential of SPH-based FSI modelling as a versatile and accurate approach for in-silico investigation of valvular pathophysiology and provide a foundation for future patient-specific assessment and cardiovascular device evaluation.