Mitral Valve-in-Valve Versus Repeat Surgical Mitral Valve Replacement in Patients With Failed Mitral Bioprostheses.

Background: Transcatheter mitral valve-in-valve (MViV) replacement has emerged as an alternative to redo surgical mitral valve replacement (redo-SMVR) in patients with failed mitral bioprostheses deemed to be at a high surgical risk. The aim of this analysis was to compare the outcomes of MViV replacement with those of redo-SMVR in patients with a failed bioprosthetic mitral valve.

Methods: We performed a study-level meta-analysis that compared MViV replacement with redo-SMVR in patients with failed mitral bioprostheses. Seven observational studies, with a total of 5083 patients, were included (1138 patients [22.4%] in the MViV replacement arm). The primary focus was all-cause mortality. Additional outcomes included major bleeding, stroke, vascular complications, and mean mitral valve gradient at follow-up.

Results: The in-hospital mortality was lower in patients who underwent MViV replacement than in those who underwent redo-SMVR (odds ratio [OR], 0.64; 95% CI, 0.53-0.78; = .0023). The short-term mortality (<1 year) was numerically lower in the MViV replacement group (OR, 0.45; 95% CI, 0.18-1.13;  = .069). At 1 year, the risk of mortality was similar in the 2 groups (OR, 0.99; 95% CI, 0.69-1.40; = .906), and at midterm follow-up (≥1 year), there was a numerically higher risk of mortality in the MViV replacement group (OR, 1.51; 95% CI, 1.00-2.29; = .051). The risk of major bleeding was significantly lower in the MViV replacement group (OR, 0.23; 95% CI, 0.10-0.56; = .01). Additionally, stroke and vascular complications were similar between the 2 groups.

Conclusions: The in-hospital mortality was lower in the MViV replacement group than in the redo-SMVR group. There were no differences in mortality at short-term (<1 year), 1-year, or midterm (≥1 year) follow-ups.