Mitral re-valve-in-valve as a new perspective for high-risk patients with prosthetic valve dysfunction: case reports.

Background: Mitral valve diseases are a common medical condition, and surgery is the most used therapeutic approach. The need for less invasive interventions led to the development of transcatheter valve implantation in high-risk patients. However, the treatment to the dysfunctions of these prosthetic valves is still uncertain, and the yield and safety of repeated transcatheter valve implantations remain unclear. Cases summary: A 69-year-old Caucasian woman with three previous mitral valve procedures performed due to rheumatic valve disease (currently with a biological prosthetic mitral valve) and a 76-year-old Latin woman with previous liver transplantation (due to metabolic-associated fatty liver disease) and biological mitral prosthesis due to mitral valve prolapse with severe regurgitation underwent mitral valve-in-valve (ViV) transcatheter implantation at the time of dysfunction of their surgical prostheses. Later, these patients developed prosthetic valve dysfunction and clinical worsening, requiring another invasive procedure. Due to maintained high-risk status and unfavourable clinical conditions for surgery, re-valve-in-valve (re-ViV) was performed. Discussion: Valve-in-valve transcatheter mitral valve implantation was approved in 2017, and, since then, it has been used in several countries, mainly in high-risk patients. Nevertheless, these prosthetic valves may complicate with stenosis or regurgitation, demanding reinterventions. Although there are favourable data for mitral ViV, re-ViV still lacks robust data to support its performance, with only case reports in the literature so far. It is possible that in high-risk patients, there is a greater benefit from re-ViV when compared with the surgical strategy. However, this hypothesis must be studied in future controlled trials.