AUTHOR=Vellguth Katharina , Barbieri Fabian , Reinthaler Markus , Kasner Mario , Landmesser Ulf , Kuehne Titus , Hennemuth Anja , Walczak Lars , Goubergrits Leonid 

TITLE=Effect of transcatheter edge-to-edge repair device position on diastolic hemodynamic parameters: An echocardiography-based simulation study

JOURNAL=Frontiers in Cardiovascular Medicine

VOLUME=Volume 9 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/cardiovascular-medicine/articles/10.3389/fcvm.2022.915074

DOI=10.3389/fcvm.2022.915074

ISSN=2297-055X

ABSTRACT=Background: 
Trans-catheter edge-to-edge repair (TEER) has developed from innovation technology to an
established treatment strategy of mitral regurgitation (MR). The risk of iatrogenic mitral stenosis after TEER is, however, a critical factor in the conflict of interest between maximal reduction of MR and minimal impairment of left ventricular filling. We aim to investigate systematically the impact of device position on the post treatment hemodynamic outcome by involving the patient-specific segmentation of the diseased mitral valve.
Materials and Methods: 
Trans-esophageal echocardiographic image data of ten patients with severe MR (age: 57±8
years, 20% female) were segmented and virtually treated with TEER at three positions by using a position based dynamics approach. Pre- and post-interventional patient geometries were pre-processed for computational fluid dynamics (CFD) and simulated at peak-diastole with patient-specific blood flow boundary conditions. Simulations were performed with boundary conditions mimicking rest and stress. The simulation results were compared with clinical data acquired for a cohort of 21 symptomatic MR patients (age: 79±6 years, 43% female) treated with TEER.
Results: 
Virtual TEER reduces the mitral valve area (MVA) from 7.5±1.6 cm2 to 2.6±0.6 cm2. Central device positioning resulted in a 14% smaller MVA than eccentric device positions. Further, residual MVA is better predictable for central than for eccentric device positions (R2=0.81 vs. R2=0.49). The MVA reduction led to significantly higher maximal diastolic velocities (pre: 0.9±0.2 m/s, post: 2.0±0.5 m/s) and pressure gradients (pre: 1.5±0.6 mmHg, post: 16.3±9 mmHg) in spite of the averaged flow rate reduction by 23% during the reduced MR after the treatment. On average, velocities were 12% and pressure gradients were 25% higher with devices in central compared to lateral or medial positions.
Conclusion: 
Virtual TEER treatment combined with CFD is a promising tool for predicting individual morphometric and hemodynamic outcome. Such a tool can potentially be used to support clinical decision making, procedure planning and risk estimation to prevent post-procedural iatrogenic mitral stenosis.