Percutaneous Rescue of Acute Left Ventricular Outflow Tract Obstruction After Mitral Valve‐In‐Valve Replacement

BACKGROUND: Left ventricular outflow tract obstruction (LVOTO) is a rare but potentially life-threatening complication of transcatheter mitral valve replacement (TMVR). Mitral valve-in-valve procedures are generally associated with a lower risk of LVOTO because of the predictable geometry provided by the surgical bioprosthesis, yet severe obstruction may still occur and precipitate abrupt hemodynamic collapse. CASE: A 79-year-old woman with a degenerated 27-mm Carpentier-Edwards Perimount mitral bioprosthesis presented with acute decompensated heart failure due to severe bioprosthetic mitral stenosis. Following multidisciplinary Heart Team evaluation, she was considered not a candidate for redo mitral valve surgery and underwent urgent transseptal valve-in-valve TMVR with a 26-mm balloon-expandable SAPIEN valve. INTERVENTION: Immediately after valve deployment, severe LVOTO developed, with an invasive peak-to-peak LV-aortic gradient of 120 mmHg. A mechanism-guided percutaneous rescue strategy was undertaken. Correction of the structural component of obstruction reduced the gradient to 60 mmHg. Persistent obstruction suggested a significant dynamic contribution, prompting selective septal branch coil embolization, which further reduced the gradient to 20 mmHg and resulted in immediate hemodynamic stabilization. CONCLUSION: Severe LVOTO after valve-in-valve TMVR may reflect both structural and dynamic mechanisms. Persistence of significant obstruction after structural correction should prompt consideration of a dynamic component and may guide effective rescue therapy.