Mitral regurgitation evolution after transcatheter tricuspid valve interventions; a sub-analysis of the TriValve registry.
Authors: Cannata F , Sticchi A , Russo G , Stankowski K , Hahn R T , Adamo M , Latib A , Lurz P , Von Bardeleben R S , Kresoja K P , Leon M , Maisano F , De Marco F , Pontone G , Taramasso M 
Published: January 2025

Abstract

Background
Transcatheter tricuspid valve interventions(TTVI) are increasingly used to treat patients with significant tricuspid regurgitation(TR).[1] The evolution of concurrent mitral regurgitation(MR) severity after TTVI is currently unknown. Increasing severity of TR is associated with declining cardiac output, while a significant increase in left ventricular preload and cardiac index have been observed in patients undergoing successful tricuspid valve surgery with functional improvement.[2,3] Physiological studies, instead, have demonstrated MR worsening in response to preload augmentation especially in the setting of left ventricular systolic disfunction; however, it is unknown whether increased left ventricular preload might translate into clinically relevant MR worsening after successful TTVI.[2,4] Gaining insights regarding the trajectories of MR severity after TTVI may significantly contribute to clinical decision-making. Indeed, it would help to define whether patients undergoing TTVI may benefit from a concurrent transcatheter procedure on the mitral valve.

Purpose
The aim of this study was to assess the evolution of MR after TTVI and to identify predictors of MR worsening and improvement.

Methods
This analysis is a substudy of the Trivalve Registry, an international registry designed to collect data on TTVI.[5] This substudy included all patients with echocardiographic data on MR evolution and excluded those with a concomitant tricuspid and mitral transcatheter valve intervention or with a history of mitral valve intervention. The co-primary outcomes were MR improvement and worsening at two timepoints: pre-discharge and 2-month follow-up.

Results
The graphical abstract is presented in Figure 1. This analysis included 359 patients with severe TR, mostly(80%) treated with tricuspid transcatheter edge-to-edge repair(T-TEER). MR improvement was found in 106(29.5%) and 99(27%) patients, while MR worsening in 34(9.5%) and 33(9%) patients at pre-discharge and 2-month follow-up, respectively. The type of transcatheter procedure has a significant impact on MR worsening and improvement. Annuloplasty and heterotopic replacement were associated with MR worsening. Independent positive predictors of MR improvement were T-TEER, acute procedural success, TR reduction, LVEDD&gt;60 mm and beta-blocker therapy while atrial fibrillation was a negative predictor. Patients with moderate-to-severe/severe MR following TTVI showed significantly higher death rates while the stratification according to MR evolution was not prognostically relevant(Figure 2).

Conclusions
MR degree variation is common after TTVI, with most cases showing improvement. Clinical and procedural characteristics may predict the MR evolution, in particular procedural success and T-TEER play key roles in MR outcomes. An effective TTVI with significant TR reduction may prevent MR worsening and possibly trigger an improvement, differently from the common belief.
Figure 1. Graphical abstract.
Figure 2. Death rates.