Left and right ventricular hemodynamic response after transcatheter mitral valve replacement
Authors: Strotmann L , Schrage B N , Koell B , Weimann J , Rommel K P , Waldschmidt L , Seiffert M , Schaefer A , Kirchhof P , Reichenspurner H , Blankenberg S , Schofer N , Kalbacher D , Conradi L , Ludwig S 
Published: November 2023

Abstract

Background
Transcatheter mitral valve replacement (TMVR) represents a novel treatment option for patients with relevant mitral regurgitation (MR), who are ineligible for surgical treatment. Although complete and predictable elimination of MR is achieved in most patients undergoing TMVR, little is known about left and right ventricular hemodynamic changes after TMVR.

Purpose
With this study, we sought to investigate left ventricular (LV) remodeling and right ventricular (RV) function in patients undergoing TMVR using data derived from non-invasive, echocardiography-based pressure volume loops.

Methods
A total of 49 consecutive patients with MR 3+ or 4+ undergoing TMVR with one of four dedicated devices were included in a prospective single-center TMVR registry between 05/2016 until 08/2022. For this study, only patients with technical success and available echocardiographic data at baseline and discharge were included. The end-diastolic and end-systolic pressure-volume relationships (EDPVR and ESPVR) were estimated non-invasively using single-beat echocardiographic measurements. VPed20 was calculated as a parameter describing the end-diastolic volume (EDV) at an end-diastolic pressure (EDP) of 20 mmHg. Ees, the slope describing the ESPVR, was calculated as surrogate parameter for LV contractility. Pulmonary artery systolic pressure (PASP), tricuspid annular plane systolic excursion (TAPSE) and RV-pulmonary artery (PA) coupling were assessed as parameters reflecting RV function.

Results
A total of 26 patients (77.0 years [IQR 73.9-80.1], N=17 [65.4%] male) with successful TMVR were included (secondary MR [N=21, 80.8%]; median LV ejection fraction 37.0% [IQR 30.7-50.7]). Overall, a significant decrease in VPed20 was observed following TMVR indicating a leftward shift of the EDPVR (165.3±75.8mL vs. 134.0±65.9mL, p&lt;0.001, Figure 1). In addition, Ees increased from 1.4±0.9 at baseline to 2.5±2.4 at discharge (p=0.0071) indicating an increaseed intrinsic LV contractility, while LV ejection fraction remained unchanged, but forward ejection fraction improved significantly (38.9±21.9% vs. 53.4±29.8%, p&lt;0.001) (Figure 1). After the procedure we observed an increased left-ventricular end-diastolic pressure (LVEDP) (22.6±4.0mmHg vs. 26.1±5.1mmHg, p=0.012). However, PASP significantly decreased (50.5±16.5mmHg vs. 35.7±10.8mmHg, p&lt;0.001). While TAPSE (18.1±5.5mm vs. 15.5±5.8mm, p=0.015) was also decreased at discharge, RV-PA coupling remained stable (0.4±0.2mm/mmHg vs. 0.5±0.2mmHg, p=0.19).

Conclusions
Non-invasive assessment of pressure volume loops before and after TMVR demonstrate an early LV reverse remodelling effect and improved systolic LV contractility, while RV performance was preserved. These results indicate the potential impact of complete MR elimination after TMVR on LV and RV function. Long-term data are needed to assess the prognostic impact of MR elimination and LV reverse remodelling following TMVR.Figure 1