New transcatheter tricuspid-valve repair device helps close larger coaptation gaps

Reuters Health - 11/06/2021 - A third-generation transcatheter tricuspid-valve repair device, the Mitra-Clip XTR system from Abbott, is showing some efficacy in dealing with larger coaptation gaps than was feasible with earlier devices.

As Dr. Rebecca T. Hahn explained in an email to Reuters Health, "Newer iterations of transcatheter edge-to-edge repair (TEER) devices are being developed to address the unmet clinical need of our patients who have severe, symptomatic tricuspid regurgitation (TR). The MitraClip XTR is one of those design enhancements which, given the longer (12 mm) clip arm lengths, was designed to address larger coaptation gaps."

In a paper in JACC: Cardiovascular Interventions, Dr. Hahn of Columbia University Medical Center, in New York City, and colleagues note to that to examine its performance they conducted a retrospective analysis of MitraClip XTR implantation for TEER treatment in 50 patients with symptomatic TR. Almost all (98%) were in New York Heart Association (NYHA) functional class III or IV.

The implantation success rate was 100%, with a median of two clips implanted per patient. Patients were divided by baseline coaptation gap sizes (CGS), including subgroup I (< 7 mm), subgroup II (7 to 10 mm) and subgroup III (>10 mm).

Significantly more clips (three) were used in subgroup III compared with subgroup II (two). One single-leaflet detachment occurred in each subgroup. There was no device embolization and there was no difference in the choice of clipping strategy.

TR was reduced by one grade in subgroup I and by two grades in subgroups II and III. NYHA functional class was reduced by one class in all three subgroups. Six-minute walk distance increased significantly in subgroups I and II but not in subgroup III. A CGS of 8.4 mm or less was predictive of a reduction to moderate or less TR.

"The data suggest that use of the MitraClip XTR for TR reduction is feasible and safe for a wide range of coaptation gaps, with significant TR reduction in all subgroups," the researchers write.

But, as Dr. Hahn pointed out, "Our study shows that while the MitraClip XTR enables treatment of larger gaps (up to 8.4 mm), patients with gaps >10 mm had lower rates of device success (defined as moderate TR) and functional improvement."

In an accompanying editorial, Drs. Philipp Lurz and Karl-Patrik Kresoja of the University of Leipzig, in Germany, agree, noting that, "The current study relevantly adds to the rapidly expanding body of evidence for transcatheter tricuspid valve repair, highlighting opportunities, but also limitations."

Dr. Kresoja told Reuters Health by email, "Newer-generation clips with larger and broader panels might be able to further reduce the strain put on the vulnerable tricuspid valve leaflets and eventually allow for treatment of even larger coaptation gaps. Yet, despite improvements in technology, it seems that an exceptionally large coaptation gap (>10 mm) will remain a limiting factor in edge-to-edge TR repair. Devices that allow transcatheter tricuspid-valve replacement instead of mere repair might fill this important therapeutic gap."

The study was supported by Abbott. Dr. Hahn and three of her coauthors report financial ties to the company.

SOURCE: https://bit.ly/3vdE9I1 and https://bit.ly/3xd9qwg JACC: Cardiovascular Interventions, online June 7, 2021.

By David Douglas



Posted on 11 June, 202128 June, 2021