Prognostic value of three-dimensional echocardiographic assessment of tricuspid valve geometry and parameters of severity in atrial and ventricular functional tricuspid regurgitation
Authors: Heilbron FR , Gavazzoni M , Florescu FD , Tomaselli MT , Cascella CA , Rella RV , Volpato VV , Oliverio OG , Ciambellotti CF , Caravita CS , Branzi BG , Parati PG , Badano LB , Muraru DM 
Published: February 2022

Abstract

Funding Acknowledgements
Type of funding sources: None.

Background
Atrial and ventricular functional tricuspid regurgitation (A-FTR and V-FTR) have recently emerged as different phenotypes of FTR. Given the difference in mechanisms that are postulated to be underlying these 2 entities, a different remodeling of tricuspid valve (TV) apparatus can occur and therefore also a specific quantitative approach could be deemed.

Aim
Aim of this study was to investigate the TV apparatus remodeling in the two different phenotypes of FTR: ventricular (V-FTR) and atrial (A-FTR) and the role of echocardiographic parameters of TV remodeling and TR severity to predict clinical outcomes.

Material and methods
The present retrospective study included consecutive patients with moderate to severe functional tricuspid regurgitation (FTR) referred for echocardiography in two Italian centers. The composite endpoint of death for any cause and heart failure (HF) hospitalization was used as primary outcome of this analysis. According to more recent guidelines, patients were considered having A-FTR if having history of long- standing atrial fibrillation, without history of pulmonary hypertension and left side heart disease.
Results. A total of 180 patients were included. Despite the right atrial volume (RAV) was not different in the 2 groups, in A-FTR tethering height was significantly lower (11.7 ±4.8 mm vs 15.0 ± 5.5 in V-FTR. p &lt;0.01) and the 3D-derived tricuspid annulus (TA) diameters were larger both in end-diastolic and mid-systolic phase (3D-TA-End diastolic- major axis: 45.2 ± 6.2 mm in A-FTR vs 42.8 ± 5.4 in V-FTR. p= 0.04; 3D-TA mid systolic major axis: 41,7 ± 6,4mm in A-FTR vs 37,9 ± 5,1 in V-FTR, P &lt;0,01). 3D-TA-End diastolic- minor axis: 39.7 ± 6.8 vs 37.1 ± 5.2. p= 0.03). Regarding the parameters of severity of FTR. patients with V-FTR had larger vena contracta (VC). either when 2D estimated or 3D (2D-VC-average: 5.3 ± 2.8 mm in A-FTR vs 6.6 ± 3.7 in V-FTR. P= 0.02; 3D-VCA: 0.9 ± 0.4 cm2 vs 1.3 ± 1.1 cm2 p= 0.02); conversely the value of 2D-ERO and regurgitant volume estimated with 2D-PISA method did not show significant difference between the 2 groups (table 1). After a median follow-up of 24 months (IQR: 2-48) 72 patients (40%) reached the primary end-point and 64 (36%) hospitalized for HF. Different predictors of combined end point were found in the 2 groups: tenting height. 2D-VC. 3D-VCA and regurgitant fraction were prognostic correlates in V-FTR; TA dimensions as well as all the parameters of severe TR. including EROA with PISA method were related to the prognosis in A-FTR (table 2).

Conclusions
Prognostic role of quantitative parameters of FTR in A-FTR and V-FTR is different, thus reaffirming the difference in underlying pathogenic mechanisms and the needing for a more specific diagnostic approach and prognostic stratification in these two FTR phenotypes