Transcatheter mitral valve options for severe mitral annular calcification.

Area of Science:

• Cardiovascular Medicine
• Interventional Cardiology
• Biomedical Engineering

Background:

• Mitral annular calcification (MAC)-associated mitral valve disease often affects high-risk patients unsuitable for surgery.
• Transcatheter mitral valve intervention (TMVI) is a developing alternative, but MAC presents unique anatomical challenges.
• Both transcatheter edge-to-edge repair (TEER) and transcatheter mitral valve replacement (TMVR) face specific hurdles due to MAC.

Purpose of the Study:

• To review the challenges and advancements in TMVI for MAC-associated mitral valve disease.
• To explore current and emerging transcatheter mitral valve replacement (TMVR) devices and techniques.
• To discuss strategies for mitigating procedural risks and improving outcomes in valve-in-MAC (ViMAC) procedures.

Main Methods:

• Review of existing literature on transcatheter mitral valve intervention (TMVI) in the context of mitral annular calcification (MAC).
• Analysis of anatomical challenges posed by MAC for transcatheter edge-to-edge repair (TEER) and transcatheter mitral valve replacement (TMVR).
• Evaluation of current and investigational TMVR devices (e.g., Tendyne, Intrepid, AltaValve, Cephea) and delivery approaches (transapical, transfemoral, transseptal, hybrid).
• Discussion of adjunctive techniques (e.g., LAMPOON, BATMAN) to address left ventricular outflow tract (LVOT) obstruction.

Main Results:

• Transcatheter edge-to-edge repair (TEER) success is limited by leaflet quality and reduced valve area in MAC.
• Transcatheter mitral valve replacement (TMVR) faces hurdles including annular morphology, insufficient calcification for anchoring, and risk of left ventricular outflow tract (LVOT) obstruction.
• Early valve-in-MAC (ViMAC) procedures had high mortality, but shifts towards transfemoral transseptal access and hybrid approaches show improved outcomes.
• Newer systems and techniques are under investigation, but mid-term mortality for ViMAC TMVR remains a concern.

Conclusions:

• Transcatheter mitral valve intervention (TMVI) is a promising but challenging option for mitral annular calcification (MAC)-associated mitral valve disease.
• Advancements in device design, delivery systems, and adjunctive techniques are crucial for overcoming MAC-related anatomical complexities.
• Continued innovation and careful patient selection are necessary to establish TMVI as a safe and effective treatment for this complex patient population.