4D ICE to guide transcatheter tricuspid edge-to-edge repair: intracardiac echocardiography compared to trans-esophageal echocardiography
Authors: Fazzari F , Biroli M , Cannata F , Ferrari C , Giacari C , Gennari M , Olivares P , Ardizzione V , Fusini L , Mantegazza V , Gripari P , De Marco F , Muratori M , Pepi M , Pontone G 
Published: January 2025

Abstract

Background
Intracardiac 3D probes have been recently employed to guide structural heart interventions and the number of patients undergoing tricuspid transcatheter edge-to-edge repair (T-TEER) is growing rapidly. While transesophageal echocardiography (TEE) has traditionally been the preferred method for guiding TEER procedures, it may not be suitable for all patients.
In contrast, intravascular cardiac echocardiography (ICE) offers several and appealing advantages by offering unique views that can aid in precise device deployment.

Purpose
This study aims to compare TEE and 4D-ICE performance in the context of percutaneous tricuspid valve interventions.

Methods
A cohort of ten patients undergoing T-TEER was prospectively enrolled. Each patient simultaneously received both TEE and 4D-ICE. The T-TEER procedure was divided into 8 steps (figure 1); at each step, TEE and 4D-ICE images were acquired and analyzed independently by two experienced echocardiographers. The steps were: Step 1: tricuspid valve anatomy assessment; Step 2: target lesion identification; Step 3: steering/valve approaching; Step 4: perpendicularity/trajectory; Step 5: clocking; Step 6: grasping; Step 7: leaflets insertion; Step 8: residual regurgitant jets. All the steps were re-evaluated each time an additional clip was necessary.

Results
A total of 10 patients were treated (mean age 76.7± 9.1; female 50%). Mean Triscore was 4.9±1.8; tricuspid regurgitation (TR) was severe (or more) in all cases. TR etiology was atrial in 9/10 and primary in 1/10 patients. Triclip and Pascal were used in 4 and 6 patients, respectively. 8/10 patients received two or more devices, whereas one device was used in 2/10 patients. Mean procedural time was 95’. Residual TR was mild in 7/10 cases, mild to moderate in 3/10.
The morphology of the valve (Step 1) was concordant to TEE in 8 cases (80%); the same target lesion (Step 2) was identified in all cases; Step 3 was feasible in 10 ICE vs 9 TEE ; perpendicularity/trajectory (Step 4) was similarly achieved; Clocking (Step 5) using 4D-ICE was feasible in 10/10 cases with respect to 3D-MPR from mid-esophageal view (7/10) and in trans-gastric views (7/10). Grasping (Step 6) was achieved with 4D-ICE and without TEE in 3/10 cases due to better image quality. Leaflet insertion of the septal leaflet was better evaluated with 4D ICE than with TEE, due to 3 cases of shadowing of the septal leaflet caused by anterior structures (aorta and interatrial septum); lateral (posterior or anterior) leaflets insertion was comparable. Finally, quantification of residual jets (Step 8) was similar.

Conclusions
In our case series, 4D-ICE was successfully utilized in all patients, offering, in some cases, superior visualization of grasping and leaflet insertion during T-TEER procedure. 4D-ICE proves to be a viable alternative to TEE and can serve as fundamental complementary tool for patients with poor TEE acoustic windows.
Step by Step analysis