Case Report: The hybrid cable technique in transcatheter mitral valve implantation with Myval THV-Technical insights from three high-risk cases

Abstract

Background: Transcatheter mitral valve implantation (TMVI) is increasingly utilized as a minimally invasive alternative for high-risk or inoperable patients with degenerated mitral prostheses or extensive mitral annular calcification (MAC). Despite its growing adoption, the procedure remains technically challenging due to complex mitral anatomy, difficulties in achieving coaxial alignment, and risks such as left ventricular outflow tract (LVOT) obstruction. The transfemoral-transseptal route, while less invasive, often provides suboptimal control and stability. Conversely, transapical access offers enhanced alignment but at the cost of increased surgical trauma. There is an unmet need for techniques that balance precision with minimal invasiveness.

Objectives: The aim of this work was to describe the technical rationale, procedural methodology, and early clinical outcomes of a novel hybrid cable-assisted TMVI approach using the Myval transcatheter heart valve (THV). This technique is designed to optimize device coaxiality and control while minimizing apical trauma.

Methods: We retrospectively reviewed three high-risk patients treated with a cable-assisted TMVI approach between October 2024 and May 2025. The technique involved the creation of a through-and-through rail between the right femoral vein and the left ventricular apex. The apical site was used exclusively for guidewire externalization, while the prosthesis was delivered entirely via the transfemoral route. Real-time transesophageal echocardiography and fluoroscopy guided the procedure. Patients were selected based on unfavorable anatomy for standard transseptal access and deemed high risk by a multidisciplinary heart team.

Results: All procedures were technically successful without surgical conversion or cardiopulmonary bypass. Patients included one woman and two men (mean age 71.7 years; range 65-78), with indications of bioprosthetic degeneration (n = 2) and MAC (n = 1). All were New York Heart Association (NYHA) class III-IV preoperatively. Procedural outcomes showed acceptable post-deployment gradients (4.5-5.8 mmHg), no paravalvular leak, and no LVOT obstruction. One patient required repositioning of a misaligned valve using the stabilized rail, avoiding hemodynamic compromise. No embolization or peri-procedural stroke occurred. All patients were discharged in NYHA class I-II.

Conclusions: This report presents the first dedicated case series of TMVI using a cable-assisted hybrid rail strategy with the Myval THV. The technique enabled precise and stable valve deployment in anatomically complex settings while minimizing myocardial trauma. Early outcomes suggest that it is a feasible, safe, and reproducible option for patients at high surgical risk or with contraindications to conventional TMVI routes. These preliminary findings support further investigation in broader clinical cohorts.

Keywords: Myval; Myval transcatheter heart valve; mitral; mitral valve; transcatheter.