A Simplified In Silico Model of Left Ventricular Outflow in Patients After Transcatheter Mitral Valve Replacement with Anterior Leaflet Laceration.

Abstract

In silico modeling has been proposed as a tool to simulate left ventricular (LV) outflow tract (LVOT) obstruction in patients undergoing transcatheter mitral valve replacement (TMVR). This study validated a simplified approach to simulate LV outflowhemodynamics in the setting of TMVR with anterior leaflet laceration, a clinical technique used to mitigate the risk of LVOT obstruction. Personalized, 3-dimensional computational fluid dynamics models were developed from computed tomography images of six patients who underwent TMVR with anterior leaflet laceration. LV outflow hemodynamics were simulated using the patient-specific anatomy and the peaksystolic flow rate as boundary conditions. The peak outflow velocity, a clinically relevant hemodynamic metric, was extracted from each simulation (vsim-peak) and compared with the clinical measurement from Doppler echocardiography (vclin-peak) for validation. In silico models were successfully developed and implemented for all patients. The pre-processing time was 2h per model and the simulation could be completed within 3h. In three patients, the lacerated anterior leaflet exposed open cells of the transcatheter valve to flow. Good agreement was obtained between vsim-peak and vclin-peak (r = 0.97, p < 0.01) with average discrepancies of 5 ± 2% and 14 ± 1% for patients with exposed and unexposed cells of the transcatheter valve, respectively. The proposed in silico modeling paradigm therefore simulated LVoutflow hemodynamics in a time-efficient manner and demonstrated good agreement with clinical measurements. Future studies should investigate the ability of this paradigm to support clinical applications.