3-year outcomes following mitral Valve-in-Ring and Valve-in-Valve procedures.

Background In patients at elevated risk for redo mitral valve surgery, transcatheter mitral valve replacement (TMVR) can be taken into consideration as a less invasive alternative. However, long-term outcome data on mitral valve-in-ring (ViR) and valve-in-valve (ViV) procedures is scarce. We herein report the 3-year outcomes following these interventions. Methods Between 2014 and 2023, 51 consecutive patients received ViR/ViV TMVR at our center. Baseline, periprocedural and 3-year outcome parameters were analyzed according to M-VARC criteria. Results Among 51 patients (70.9±13.6 years, STS-Score 3.3±2.3 %, LVEF 50±12%), 19 underwent ViR and 32 ViV TMVR. Follow-up ranged from 1 to 71 months. The 30-day mortality rate was 5.9% (3/51 patients). Over time, access shifted from transapical to transseptal (p for trend <0.01). Rehospitalization, neurological events and myocardial infarction occurred in 2.0% (1/51 patients), 2.0% (1/51 patients) and 0.0% of the cases, respectively. No structural valve failure was observed. Functional failure was 3.9% of cases due to significant residual mitral regurgitation. Most paravalvular leak occluder implantations were performed in ViR patients (6/9, 66.7%) (4 rigid rings and 2 semi-rigid rings). Three-year survival was 87.5% for ViR and 83.4% for ViV, with no differences between groups. Conclusions Mitral ViR and ViV procedures demonstrate acceptable safety and clinical efficacy up to 3 years. Rigid annuloplasty rings are associated with an increased risk of significant residual regurgitation. Over the last decade, a clear transition from the transapical to the transseptal access has been observed, further reducing procedural trauma in this high-risk subset of patients.