First-in-human study of the K-Clip™ transcatheter annular repair system for severe functional tricuspid regurgitation.

Background: Severe TR is associated with impaired prognosis while limited interventional options available. The purpose of this observational first-in-human experience with the K-Clip™ transcatheter tricuspid annular reconstruction system is to investigate its feasibility, safety as well as short-term clinical impact on patients with severe functional tricuspid regurgitation (TR).

Methods: In this compassionate-use, prospective, multi-center, single-arm study, 15 patients with severe symptomatic functional TR were treated with the K-Clip™ system and followed up at 30 days after discharge. Feasibility endpoints consisted of safety (major clinical cardiovascular events (MACEs), echocardiographic, clinical and functional endpoints.

Results: All the 15 patients (9 males, 72.67 ± 9.42 years of age) successfully received implants and no MACEs were reported throughout the study at 30 days. Between baseline and 30 days, echocardiography showed remarkable reduction of tricuspid annular circumference and area by 14.30% and 25.96%. Improvement of ≥ + 2 grade and ≥ +3 grade TR was presented in 9/15(60.00%) and 4/15(26.67%) respectively while 10/15(66.67%) of patients had ≤ moderate TR. Clinical evaluation indicated that 86.67% of patients were finally in NYHA functional class I or II (p<0.001) and overall Kansas City Cardiomyopathy Questionnaire score improved from 62.28 ± 18.97 to 77.90 ± 11.70 (p = 0.016).

Conclusion: Our first-in-human results of the transcatheter tricuspid annular reconstruction using the K-Clip™ system demonstrated initial favorable procedural success, acceptable safety and remarkable TR reduction in consistent with significant clinical improvement. Larger-scaled prospective trials with longer follow-up duration are warranted to further determine whether these promising findings could be promoted to a broader population in the long term.