Surgical or Transcatheter Mitral Valve Replacement After Prior Bioprosthesis or Ring Implantation: A Landmark Analysis of Early and Long-Term Outcomes

<b>Background:</b> In recent years, the use of transcatheter valve-in-valve implantation in the mitral position (TMVI) for the treatment of mitral valve pathology following ring or bioprosthetic implantation has emerged as a less invasive option in comparison to repeated mitral valve surgery (RMVS). We aimed to compare the early and mid-term results of these two strategies. <b>Method:</b> We retrospectively analyzed all patients who underwent a mitral intervention in our institution between 2005 and 2022. Applying the exclusion criteria, 41 subjects were analyzed: 23 underwent RMVS, while 18 underwent a TMVI. The time-dependency treatment effect was approached using a landmark analysis, applying the Kaplan-Meier analysis at different time points. <b>Results:</b> The two study groups were comparable in terms of age (<i>p</i> = 0.18), gender (<i>p</i> = 0.78), body surface area (<i>p</i> = 0.33), and EuroSCORE II (<i>p</i> = 0.06). No patients died perioperatively or had a stroke. Two patients in each group died within the first 30 days following the procedure (RMVS 8.3% vs. TMVI 11.1%; <i>p</i> = 0.75). Eighteen patients had died at follow-up; two underwent re-intervention on their mitral valve (one in each group). The mean survival was not statistically different between groups (RMVS 8 ± 1.1 years, 95% CI 5.8-10.2, vs. TMVI 4.79 ± 0.82 years, 95% CI 3.1-6.4; log-rank = 0.087). A landmark analysis of survival after four years showed significantly worse survival for patients in the TMVI group in comparison with those treated surgically (log-rank = 0.047). <b>Conclusions:</b> TMVI and RMVS are both effective strategies with similar short-term outcomes. However, patients in the TMVI group showed a significantly lower survival rate after four years.