Assessment of right ventricular function in patients with severe secondary tricuspid regurgitation, following to the TVARC recommendations: association with outcome
Authors: Galloo X , Dietz M F , Prihadi E A , Fortuni F , Van Der Bijl P , Bax J J , Hahn R T , Ajmone Marsan N 
Published: October 2024

Abstract

Introduction
Severe tricuspid regurgitation (TR) is associated with increased mortality if left untreated. Recently, the Tricuspid Valve Academic Research Consortium (TVARC) has published standardized definitions of disease aetiology and severity, as well as endpoints for future clinical trials. Right ventricular (RV) function assessment represents one of the cornerstones for risk stratification in these patients, but current guidelines do not propose specific cut-off values for the echocardiographic measures. Also, the thresholds proposed by the TVARC have been derived from normative value and not yet validated in large cohorts of TR patients.

Purpose
To test the prognostic value of the TVARC proposed echocardiographic cut-offs for grading RV-dysfunction (figure1) in a large real-world cohort of patients with severe secondary TR (STR).

Methods
Consecutive patients from a single centre with first diagnosis of severe secondary STR, and without a cardiac implantable electronic device, were included. Tricuspid annulus plane systolic excursion (TAPSE), RV global and free wall strain (RVGLS and RVFWLS) and fractional area change (FAC) were used to measure RV function. The study endpoint was all-cause mortality, censored for tricuspid valve intervention.

Results
A total of 1043 patients (mean age 69 ± 13 years, 43% male), were included. Approximately half of the population (45%) was in NYHA class III or IV and 52% was treated with loop diuretics. Overall patients showed mild RV-dilatation (RV end-diastolic area indexed 12.2 [10.1-15.2cm2/m2]) and moderate-to-severe right atrial dilatation (right atrial maximal area indexed: 13.9 [11.0-17.5cm2/m2]). Using the proposed cut-off values, strain analysis identified a higher number of patients with impaired RV function as compared to standard echocardiographic parameters (89% based on RVGLS; 80% based on RVFWS, 61% based on TAPSE and 54% based on RVFAC).
During a median follow-up of 51 [IQR 6 - 98] months, 445 (43%) patients died. The Kaplan-Meier survival curves for each echocardiographic parameter of RV-function are shown in Figure 1. TAPSE, which is the most widely used RV-function parameter, was able to clearly identify patients at high and intermediate risk when mildly, moderately and severely impaired. However, patients with normal TAPSE were still at intermediate risk when RVFWLS was (even mildly) reduced (figure 2). We therefore propose a stepwise practical approach including the measure of RVFWLS when measuring normal TAPSE, in order to possibly re-stratify patients into a higher risk group (Figure 2). This novel grading approach remained independently associated with all-cause mortality after correcting for relevant clinical and echocardiographic variables on multivariable analysis.

Conclusion
Novel TAVRC cut-off values for RV function show prognostic value in patients with severe STR; particularly the combination of TAPSE and RVFWLS could be use in clinical practice for risk stratification.Figure 1Figure 2