Characterization of coaptation gap in patients receiving tricuspid transcatheter edge-to-edge repair: initial observations from the bRIGHT TriClip study

Abstract

Funding Acknowledgements Type of funding sources: Private company. Main funding source(s): Abbott Background As tricuspid transcatheter edge-to-edge repair (TEER) gains momentum, the proper measurement of coaptation gap to determine optimal patients for this therapy becomes increasingly important. Currently, a single septo-lateral measurement from the short-axis transgastric (SAX TG) or RV inflow/outflow biplane view is commonly used as the representative coaptation gap measurement for a patient. However, this measurement is not necessarily performed at the intended location for TEER and may overestimate the coaptation gaps to be treated. Purpose To characterize the coaptation gap in patients receiving tricuspid TEER which may provide insights on how to best determine eligibility for edge-to-edge repair. Methods bRIGHT is a prospective, multi-center, single arm post-market study evaluating the safety and effectiveness of the TriClip device in symptomatic patients with severe tricuspid regurgitation. Detailed echocardiographic coaptation gap measurements were performed on the first 46 subjects with available echo data by two experienced echocardiographers. Coaptation gap was measured at four levels in the SAX TG view (Figure 1) and also at the resulting long axis view from a orthogonal view taken from a RV inflow/outflow view obtained at the anterior, mid and posterior aspect of the tricuspid valve (Figure 2). Results The biplane RV inflow/outflow and SAX TG views were available in 91% (42/46) and 93% (43/46) of subjects, respectively. From the SAX TG view, coaptation gap measured 9.0 ± 3.9 and 4.9 ± 2.7 mm in the central and mid regions of the anterior-septal coaptation line, and 7.6 ± 3.4 and 4.0 ± 2.1 mm in the central and mid regions of the septal-posterior coaptation line (Figure 1). The largest coaptation gap presented between the anterior and septal leaflets in 78% (33/43) of subjects, with the gap extending across the anterior-septal and septal-posterior coaptation lines in 98% (42/43) of subjects. Coaptation gap measured 6.2 ± 2.8, 6.6 ± 2.8 and 6.0 ± 3.5 mm in the anterior, mid and posterior aspects of the RV inflow/outflow view (Figure 2). In subjects with both views available, the SAX TG view resulted in larger coaptation gap measurements (+3.4 ± 3.0 mm) in 95% (38/40) of subjects. A significant, positive correlation was observed between the maximum biplane and transgastric measurements (rho = 0.648, p < 0.0001). Conclusion A single septo-lateral measurement may overestimate the actual gap size and potentially exclude patients who are viable candidates for TEER. Measurements in both the SAX TG and RV inflow/outflow biplane should be taken into account when determining appropriateness of a given anatomy for tricuspid TEER Future work in larger cohorts is needed to determine which coaptation gap measurements are predictive of procedural outcomes and how these measurements may influence treatment strategy. Abstract Figure 1 Abstract Figure 2

The Evolving Role of Transcatheter Tricuspid Valve Edge-to-Edge Repair in Tricuspid Regurgitation

“…The suitable anatomical structure of TV includes leaflet lengths exceeding 7 mm, a coaptation gap between 3 and 7 mm, and a central TR jet within the anteroseptal commissure [22,51]. Notably, 30-day follow-up data from the bRIGHT study have suggested that T-TEER achieves similar TR decreases among patients with coaptation gaps of <7 mm, 7-10 mm, and >10 mm [52]. Moreover, patients without cardiac implantable electronic devices are preferred for this procedure.…”

Multimodality imaging for transcatheter tricuspid valve repair and replacement

“…Evaluation of tricuspid leaflet morphology is relevant in pre-procedural assessment as increasingly complex leaflet morphologies may be unfavorable for procedural efficacy of TEER ( 39 , 40 ). Importantly, coaptation gaps should only be measured from the transgastric 2D short-axis views if the leaflet tips are imaged; studies suggest that this view frequently overestimates these gaps compared to the RV inflow-outflow views ( 41 ). TV morphology and leaflet characterization may thus be more accurately assessed with 3D echocardiography and multi-planar reconstruction.…”