Magnetic resonance-based computational modelling of healthy and prolapsing mitral valves to quantify the load transfer between the mitral apparatus and the ventricular myocardium

Replacement myocardial fibrosis of the left ventricle (LV) is frequently observed in mitral valve prolapse (MVP) patients, possibly due to altered load transfer between the mitral valve (MV) and LV wall. Leveraging cardiac magnetic resonance (CMR) imaging, we propose an improved finite element (FE) model to quantify in vivo this load transfer in both healthy and MVP-affected valves. The framework was tested on 6 subjects (3 healthy, 3 with MVP). CMR images were realigned via normalized cross-correlation; MV leaflets were reconstructed in a stress-free state, discretized and paired with a functionally equivalent chordal model. Chordae were partially removed in prolapsing segments and their length tuned. Valve closure was simulated under physiological pressure, incorporating anisotropic, hyperelastic tissue properties and subject-specific annular and papillary muscle (PM) motion. PMs head anatomy was separately simulated to assess stress transfer to the LV wall. Simulations reliably reproduced in vivo MV closure, with median discrepancies in the order of imaging resolution. FE results suggest that at peak systole MVP is associated to increased stress at the base of the anterolateral and posteromedial PMs (values averaged over the subgroups: σ AL = 0.16 MPa, σ PM = 0.20 MPa vs. σ AL = 0.11 MPa, σ PM = 0.12 MPa) and to greater annular force at the insertion of the prolapsing mid-posterior cusp (values averaged over the subgroups: RF P 2 = 0.03 N vs. RF P 2 = 0.02 N) vs. healthy controls. The framework reliably quantified MV–LV load transfer and its application to larger cohorts could provide valuable clinical insights.