Whisenant B, Kapadia SR, Eleid MF, et al. - Researchers performed this registry-based prospective cohort study to evaluate contemporary results of SAPIEN 3 (Edwards Lifesciences) mitral valve-in-valve (MViV) replacement. They examined patients enrolled in the Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapy Registry from June 2015 to July 2019. One-year mortality was the primary efficacy endpoint. Thirty-day death, New York Heart Association–defined heart failure, and mitral valve performance were secondary endpoints. Between June 2015 and July 2019, transseptal or transapical MViV implant was received by 1,529 patients at 295 hospitals. A high technical success, low 30-day and 1-year mortality, significant improvement of heart failure symptoms, as well as sustained valve performance were reported in relation to transcatheter MViV using the SAPIEN 3 transcatheter heart valve. Considering transseptal MViV as a choice for most patients with failed surgical bioprosthetic valves and favorable anatomy was recommended.