Prospective Study of TMVR Using Balloon-Expandable Aortic Transcatheter Valves in MAC: MITRAL Trial 1-Year Outcomes

Area of Science:

• Cardiovascular Medicine
• Interventional Cardiology
• Medical Devices

Background:

• The MITRAL (Mitral Implantation of Transcatheter Valves) trial is the first prospective study to assess the feasibility of valve-in-mitral annular calcification (ViMAC).
• This study utilizes balloon-expandable aortic transcatheter heart valves for ViMAC procedures.

Purpose of the Study:

• To evaluate the 1-year outcomes of valve-in-mitral annular calcification (ViMAC) in the MITRAL trial.
• To assess the safety and efficacy of ViMAC in high-risk surgical patients with severe mitral annular calcification and symptomatic severe mitral valve dysfunction.

Main Methods:

• A multicenter prospective study enrolled 31 high-risk patients at 13 U.S. sites.
• Patients had severe mitral annular calcification and symptomatic severe mitral valve dysfunction.
• Procedures included transatrial, transseptal, or transapical access; pre-emptive alcohol septal ablation was used after initial cases.

Main Results:

• Technical success was achieved in 74.2% of patients.
• At 1 year, 83.3% of patients improved to New York Heart Association functional class I or II.
• Mean mitral valve gradient was 6.1 mm Hg, with ≤1+ mitral regurgitation in all patients.

Conclusions:

• ViMAC demonstrated symptom improvement and stable transcatheter heart valve performance at 1 year.
• Pre-emptive alcohol septal ablation may prevent left ventricular outflow tract obstruction (LVOTO) in at-risk patients.
• Further research is needed to fully evaluate the safety and efficacy of ViMAC.