Late Hemodynamic Improvement of Mitral Prosthesis After Transcatheter Mitral Valve In Valve Implantation

Background: Trans-catheter Mitral valve in valve (MVIV) implantation has become a standard of care for the treatment of failed mitral bioprosthesis in high risk patients. It has been shown to provide good early clinical outcomes. However, early gradients across the prosthesis are usually high. We evaluated the late hemodynamic performance of the prosthesis and its effect on late functional capacity.

Methods: 15 patients underwent transapical transcatheter valve-in-valve implantation for failed bioprosthesis. From this group, 13 patients underwent MVIV implantation. Mean age was 77±13 years and nine were female (69%). Mean time from original MV replacement to MVIV procedure was 11± 4 years. Mean Logistic EuroScore mortality risk was 32 ± 16. Follow-up was 100% completed with a mean time of 18±15 months.

Results: Preoperatively, all patients had structural deterioration, 10 presented with severe mitral prosthesis regurgitation, 3 patients suffered from stenosis. All patients underwent successful transapical MVIV implantation with the Edwards Sapien balloon expandable valve (11 patients with 26mm and 2 with 29mm). There was no in-hospital mortality. Mean and median hospital lengths of stay were 15 ± 18 and 7 days. There were no major complications, except for one patient with major femoral access bleeding. At last follow-up, all patients were alive and in NYHA functional class I or II significantly lower than pre-operatively (p=0.016). Echocardiography follow-up demonstrated none or trivial mitral regurgitation in eleven patients and mild in two. Peak and mean gradients changed from 25±5 and 10±4 at baseline, to 18±6 and 8±4 immediately post-op to 15±3 and 6±2, at follow-up (p=0.017).

Conclusions: Transcatheter transapical mitral valve-in-valve implantation is an excellent alternative to conventional redo MV surgery for failed bioprosthesis, in high-risk patients. Early post procedure gradients across the MV are high but at mid term follow-up a significant reduction of gradients is observed.