Transatrial Balloon-Expandable Valve Implantation for Severe Mitral Annular Calcification With Native Leaflet Sealing.

BACKGROUND

Severe mitral annular calcification (MAC) limits mitral intervention options. Transseptal valve-in-MAC (ViMAC) transcatheter mitral valve replacement (TMVR) risks neo-left ventricular outflow tract (neo-LVOT) obstruction and paravalvular leak, while surgical replacement requires extensive annular reconstruction.

CASE SUMMARY: We report 3 high-risk patients with severe MAC (computed tomography [CT]-based MAC scores 7-10) who underwent open transatrial valve-in-MAC TMVR via a balloon-expandable valve after CT-based simulation and multidisciplinary heart review identified increased risk of valve malapposition or neo-LVOT obstruction precluding transseptal approach. Native anterior mitral leaflet tissue was preserved, everted, and fixed to the bioprosthetic valve cuff, creating a seal to address frame-annulus gaps.

DISCUSSION: All patients achieved stable prosthesis apposition with no paravalvular leak, stable LVOT gradients, and significantly improved functional status at their 3-month follow-up. Two underwent concomitant aortic root replacement; one underwent concomitant septal myectomy and tricuspid repair.

TAKE-HOME MESSAGES: CT-based simulation facilitates identification of patients who face increased risk of complications with transseptal TMVR. This series demonstrates reproducibility of native anterior mitral leaflet fixation to address frame-annulus gaps in transcatheter mitral replacement.