Transcatheter mitral valve replacement in a complex mitral annular calcification anatomy

Transcatheter mitral valve replacement (TMVR) is emerging as a feasible alternative to conventional surgical intervention in patients at high surgical risk, also those with severe mitral annular calcification (MAC). However, the presence of a previously implanted self-expanding transcatheter aortic valve prosthesis introduces considerable technical difficulties, especially due to the risk of left ventricular outflow tract obstruction.

To our knowledge, it is among the very few reported cases of combined percutaneous interventions with a self-expanding valve in the aortic position and a balloon-expandable valve in the mitral position. During the procedure, circulatory arrest occurred, followed by the development of cardiac tamponade; both complications were rapidly and effectively managed. Subsequently, the patient experienced acute heart failure caused by a residual, procedure-related defect in the atrial septum, which required closure via a percutaneous approach.

This case underscores the significant technical and clinical challenges associated with TMVR in the setting of MAC, particularly in patients with a pre-existing self-expanding aortic bioprosthesis. Intra-procedural complications, including circulatory arrest, cardiac tamponade, and procedure-related atrial septal defect, required rapid treatment and solution.