The K-clip?: Time for a new tricuspid valve focal annuloplasty system

Severe functional tricuspid regurgitation (TR) is a common condition independently correlated with unfavorable clinical outcomes and significant increase in mortality rate [ [1] Sisinni A. Taramasso M. Praz F. et al. Concomitant transcatheter edge-to-edge treatment of secondary tricuspid and mitral regurgitation: an expert opinion. J Am Coll Cardiol Intv. 2023; 16: 127-139 Crossref Scopus (2) Google Scholar ]. When faced with the challenge of an increased surgical risk and unfavorable prognosis associated with conservative treatment, transcatheter technologies emerged as a promising and viable alternative [ [2] Sarraj-Asil A. Diez-Villanueva P. Insight into functional tricuspid valve regurgitation pathogenesis, pathological stages, and surgical management. Int J Cardiol. 2021; 338: 161-167 Abstract Full Text Full Text PDF PubMed Scopus (0) Google Scholar , [3] Estévez-Loureiro R. Barreiro-Pérez M. Transcatheter tricuspid valve replacement: beyond symptom improvement. Int J Cardiol. 2023; 374: 85-86 Abstract Full Text Full Text PDF PubMed Scopus (0) Google Scholar ]. Despite several treatment options had been introduced, such as edge-to-edge leaflet approximation, direct annuloplasty, orthotopic valve replacement and heterotopic caval valve implantation, severe functional TR remains appallingly untreated [ [4] Praz F. Muraru D. Kreidel F. et al. Transcatheter treatment for tricuspid valve disease. EuroIntervention. 2021; 17: 791-808 Crossref PubMed Scopus (77) Google Scholar ]. Different reasons might explain that unmet clinical need for treatment, including a) lack of comprehensive awareness from physicians persisting in considering TR as a passive bystander to the more impactful diseases affecting the left heart and pulmonary vasculature, b) advanced right ventricular (RV) dysfunction and/or severe pulmonary hypertension, especially in context of a fixed pre-capillary component, c) severely impaired quality of life, due to possible futility and d) challenging anatomies, such as >3 leaflet tricuspid valve or large gaps, transvalvular leads that would prevent proper placement of the device (especially leaflet approximation devices) and, mostly, extremely dilated tricuspid annulus (TA).