Whisenant B, Kapadia SR, Eleid MF, et al. - This registry-based prospective cohort study was performed to determine contemporary results of SAPIEN 3 (Edwards Lifesciences) transcatheter mitral valve-in-valve (MViV) replacement. Using the Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapy Registry, 1,529 patients who had transseptal or transapical MViV implant at 295 hospitals between June 2015 and July 2019 were identified and analyzed. In this study, transcatheter MViV using the SAPIEN 3 transcatheter heart valve was shown to be related to high technical success, low 30-day and 1-year death, significant improvement of heart failure symptoms, and sustained valve performance. Experts advised considering transseptal MViV as a choice for most patients with failed surgical bioprosthetic valves and favorable anatomy.