Outcomes of Transcatheter Mitral Valve Implantation for Failed Bioprostheses and Annuloplasty Rings

Transcatheter mitral valve implantation (TMVI) is increasingly used in failed bioprostheses and annuloplasty rings as a less invasive alternative to redo-surgery in selected patients, with promising results. This retrospective single-centre study aims to provide additional insight into clinical outcomes and its determinants following TMVI.

Data of all TMVI procedures (n = 88) performed between February 2014 and June 2024 were retrospectively analysed. The primary end-points were 1-year mortality and the Mitral Valve Academic Research Consortium (MVARC) composite end-points. Secondary outcomes included complications and echocardiographic outcomes.

Overall, in-hospital, 30-day, and 1-year mortality rates were 6.8%, 5.8%, and 16.5%, respectively. No significant differences were observed between transseptal and transapical approach (20.0 vs 13.2%, P = .439) or between valve-in-valve and valve-in-ring procedure (16.3 vs 18.2%, P = .828). At 1-year follow-up, only one patient presented with mitral regurgitation ≥ grade 2. However, a post-procedural mean pressure gradient (MPG) ≥5 mm Hg was observed in 51 patients (58%). In multivariate analysis, higher post-procedural MPG was associated with increased mortality risk (P = .047; hazard ratio [HR] = 1.23; 95% CI, 1.00-1.51), whereas technical success was associated with reduced mortality risk (P = .014; HR = 0.12; 95% CI, 0.02-0.65).

Transcatheter mitral valve implantation provided acceptable mid-term mortality irrespective of procedure type and access route, with excellent technical success. Furthermore, mid-term follow-up showed near-complete elimination of mitral regurgitation. However, a high rate of post-procedural relevant mitral stenosis was observed, which may have an impact on mortality. In the light of the anticipated increase in TMVI procedures, we advocate for larger prospective studies to investigate the long-term determinants of mortality.

As this study was retrospective and based on previously collected clinical data, clinical trial registration was not required.