Transcatheter "valve-in-valve" mitral valve replacement for patient-prosthesis mismatch: Chronicle of a death foretold.

Severe mitral annular calcification (MAC) may represent a challenging issue which can lead to poor outcomes and serious issues such as patient-prosthesis mismatch (PPM). The potential harmful effect of PPM must be prevented through the use of alternative techniques that allow mitral valve replacement with adequately sized bioprostheses in patients with MAC. PPM should be recognized as a contraindication for transcatheter valve-in-valve replacement as it leads to poor outcomes and early prosthetic degeneration.