Management of life-threatening deformation of obstructive transcatheter mitral valve replacement bioprosthesis with balloon inflation in left ventricular outflow tract: a case report.

Background: Left ventricular outflow track (LVOT) obstruction (LVOTO) is a severe complication of transcatheter mitral valve replacement (TMVR) procedures, with an uncertain prognosis and only few strategies available to prevent its occurrence. TMVR is thus contraindicated in some patients because of a high risk of LVOTO onset. We demonstrate how LVOTO can be managed with a balloon inflation in the LVOT and a D-shaped deformation of the bioprosthetic valve. Case summary: A 64-year-old female presented with acute pulmonary oedema 2 weeks following aortic valve replacement and aorto-coronary bypass surgeries. A concomitant mitral stenosis, secondary to significant calcifications of the mitral annulus, was not treated during the procedure. After surgery, the mitral valvulopathy caused an acute heart failure and TMVR was performed by the heart team. The procedure was complicated by a cardiac arrest secondary to the onset of LVOTO which was managed by a balloon inflation in the LVOT and an alcohol septal ablation. Two-year follow-up shows a favourable outcome of the patient and good function of the prosthetic valve despite its deformation. Discussion: This case highlights the successful management of a LVOTO following valve-in-mitral annular calcification TMVR by balloon inflation in the LVOT. It is strongly recommended to place a 'rescue' guidewire in transaortic position during TMVR in order to manage the potential onset of acute LVOTO.