Characterization of Tricuspid Valve Anatomy and Coaptation Gap in Subjects Receiving Tricuspid Transcatheter Edge-To-Edge Repair: Observations From the bRIGHT TriClip Study

Background: Transcatheter edge-to-edge repair (TEER) for the treatment of tricuspid regurgitation (TR) has experienced fast adoption following commercial approval. Defining the appropriate target population for TEER therapy is important to guide patient selection. The aim of this study was to characterize tricuspid valve anatomy and coaptation gap in subjects receiving TEER for the treatment of TR in a contemporary postmarket setting.

Methods: The bRIGHT study is a prospective, multicenter, single-arm, postmarket study evaluating the safety and effectiveness of the TriClip device. Procedural outcomes included implant success, acute procedural success, TR severity, major adverse events, single-leaflet device attachment, and embolization through 30 postprocedure days. Tricuspid valve characteristics, including morphology, annulus size, and leaflet mobility, were assessed via two-dimensional transesophageal echocardiography from the screening visit by an independent echo core lab to characterize subject variability. Coaptation gap measurements were taken in both the transgastric short-axis (TG SAX) and RV inflow/outflow views.

Results: The independent echo core lab performed a detailed assessment of the tricuspid valve on 135 consecutive subjects with available TG SAX views from 24 sites. Tricuspid valve morphologies included 2 to 5 leaflets, with a non-trileaflet valve in 28% of subjects and ≥4 leaflets in 21% of subjects. The etiology of TR was functional in 91% (96/105), mixed in 7% (7/105), and lead induced in 2% (2/105) of subjects. Leaflet mobility was mildly restricted in 69% (78/113) and moderately restricted in 7% (8/113) of subjects. Annulus diameter averaged 4.7 ± 0.7 cm with a range of 2.5 to 6.2 cm. From the TG SAX view, the coaptation gap measured 8.1 ± 3.1 and 5.2 ± 2.3 mm in the central and mid regions of the anterior-septal coaptation line and 6.6 ± 3.2 and 3.8 ± 2.1 mm in the central and mid regions of the septal-posterior coaptation line, respectively. From the right ventricular inflow/outflow view, the coaptation gap measured 4.7 ± 2.4, 5.2 ± 2.4, and 4.6 ± 3.0 mm in the anterior, mid, and posterior regions of the tricuspid valve, respectively. Thirty-day TR reduction (by number of grades) was similar among subjects with coaptation gaps of <7 mm, 7 to 10 mm, and >10 mm.

Conclusion: A broad range of anatomies was observed in this postmarket population. Characterization of the tricuspid valve and coaptation gap will help to better understand and better define the target patient population for tricuspid TEER therapy.