Impact and limitations of 3D computational modelling in transcatheter mitral valve replacement-atwo-centre Dutch experience.

Abstract

Transcatheter mitral valve replacement (TMVR) has emerged as aminimally invasive alternative to mitral valve surgery for patients at high or prohibitive operative risk. Prospective studies reported favourable outcomes in patients with annulus calcification (valve-in-mitral annulus calcification; ViMAC), failed annuloplasty ring (mitral valve-in-ring; MViR), and bioprosthetic mitral valve dysfunction (mitral valve-in-valve; MViV). Multi-slice computed tomography (MSCT)-derived 3D-modelling and simulations may provide complementary anatomical perspectives for TMVR planning. We aimed to illustrate the implementation of MSCT-derived modelling and simulations in the workup of TMVR for ViMAC, MViR, and MViV. For this retrospective study, we included all consecutive patients screened for TMVR and compared MSCT data, echocardiographic outcomes and clinical outcomes. Sixteen out of 41patients were treated with TMVR (ViMAC n = 9, MViR n = 3, MViV n = 4). Eleven patients were excluded for inappropriate sizing, 4for anchoring issues and 10for an unacceptable risk of left ventricular outflow tract obstruction (LVOTO) based on 3D modelling. There were 3procedure-related deaths and 1non-procedure-related cardiovascular death during 30days of follow-up. LVOTO occurred in 3ViMAC patients and 1MViR patient, due to deeper valve implantation than planned in 3patients, and anterior mitral leaflet displacement with recurrent basal septum thickening in 1patient. TMVR significantly reduced mitral mean gradients as compared with baseline measurements (median mean gradient 9.5(9.0-11.5) mm Hg before TMVR versus 5.0(4.5-6.0) mm Hg after TMVR, p = 0.03). There was no residual mitral regurgitation at 30days. MSCT-derived 3D modelling and simulation provide valuable anatomical insights for TMVR with transcatheter balloon expandable valves in ViMAC, MViR and MViV. Further planning iterations should target the persistent risk for neo-LVOTO.