Assessment of Transcatheter Heart Valve Migration and Embolization Risk Following Valve-in-MAC

Transcatheter Valve Embolization and Migration (TVEM) is a rare, but catastrophic event where the prosthesis moves due to heamodynamic forces acting on the frame. TVEM following Transcatheter Mitral Valve Replacement (TMVR) is largely undocumented. Haemodynamic forces cannot be estimated during pre-procedural planning and conventional imaging does not allow to compute them after replacement. To shed light on this issue, this study focusses on modelling haemodynamics after TMVR in 3 patients with Mitral Annular Calcification (MAC) known as Valve-in-MAC (ViMAC). Three-dimensional flow simulations are performed using the computational fluid dynamics (CFD) package STARCCM+. Results of the simulation are processed to compute the fluid forces acting on the device and pressure gradients in the left ventricular outflow tract (LVOT). Anatomical measurements are performed on CT data sets to assess the mitral valve size and shape, the extent and location of the calcification and the size of the LVOT after implantation. Our results show that the force distribution on the device is largely influenced by LVOT anatomy and contraction patterns.