Accuracy of the simple 3D transthoracic echocardiography in the definition of tricuspid valve and right ventricle anatomy
Authors: Bruno N , Russo M , Pergolini A , Sbaraglia F , Cammardella A G , Ranocchi F , Polizzi V , Musumeci F 
Published: June 2023

Abstract

Funding Acknowledgements
Type of funding sources: None.

Introduction
The interest in the "forgotten" valve has re-emerged in recent years in consideration of the high mortality rate related to the highest degrees of TR and the recognition of a large amount of patients who remains under treated. Transcatheter tricuspid valve interventions (TTVI) represent a valuable option in high risk surgical candidates when specific anatomic criteria are met. Tailoring the most suitable therapeutic percutaneous strategy for each patient is crucial: an accurate screening aims to quantify regurgitation grade and fully understand the underlying mechanism. Transthoracic and transesophageal is used to assess jet location, leaflets anatomy and motion. ECG-gated Cardiac TC is necessary for the selection of annuloplasty or replacement techniques.

Purpose
Aim of the study is to compare three different imaging modalities as 3D transthoracic echocardiography (TTE), transesophageal one (TOE) and ECG-gated Cardiac CT for the definition of tricuspid valve anatomy, annular dimensions and right ventricle geometry in patients screened for TTVI.

Methods
Twenty-one (Age 79 ± 7 years, Female 72%) patients, referred with a diagnosis of at least severe TR in evaluation for percutaneous treatment, were prospectively enrolled in the study and underwent TTE, TOE and Cardiac CT. All measurements were performed in double blind by three different operators and compared.

Results
In the comparison between 2D/3D TTE and 2D/3D TOE no statistically significant differences were found regarding the evaluation of the valve anatomy, the site of regurgitation and the underlying mechanism (TTE vs TOE: 3D septo-lateral diam 45,8± 4,92 vs 45,87 ± 4,98 mm, p = 0.87; 3D antero-posterior diam 43,5 ± 4,58 vs 43,5 ± 4,53 mm, p = 0.59; Circularity index 0,75± 0,08 vs 0,76± 0,08, p = 0.98; 3D Annular area 16,48±3.9 vs 15,97±3,75 cm2, p = 0.77; Annular perimeter 14,82±1,62 vs 14,93±1,9 cm, p = 0.54). From the double-blind comparison between 3D TTE and Cardio CT, no differences emerged regarding anatomic annulus parameters (area 17,58± 3 vs 17.71±4,3 cm2, p = 0.1; perimeter 14,89±1,6 vs 14,29±1 cm, p = 0.5; maximum diameter 50,5 ± 5 vs 50,6 ± 5.1mm, p = 0.19; minimum diameter 40,25±3.8 vs 41.16± 4,9mm, p = 0.28). Similarly, in the study of right ventricular dimensions, obtained through 3D volumetric reconstruction, TTE was not statistically different to Cardiac CT (3DTTE vs CT: RVD1 51,14 ±2,54 vs 49,42 ± 5 mm, p = 0.5; RVD2 40,62±7,9 vs 40±11 mm,p = 0.7; RVL 72, 12±7 vs 72,12±11 mm, p = 0.8).

Conclusions
Three-dimensional trans-thoracic echocardiography showed an optimal performance to define tricuspid valve anatomy and right ventricle dimensions when compared with other imaging methods. 3D TT can be safely used for an overall first line in periprocedural evaluation of patients candidates for TTVI, allowing for elaborated study of the characteristics of TR through MPR reconstructions, annular and valvular anatomy, right chambers size and function.