Prognostic Impact of Residual Moderate Mitral Regurgitation Following Valve-in-Valve Transcatheter Aortic Valve Implantation

INTRODUCTION: The impact of mitral regurgitation (MR) on valve-in-valve transcatheter aortic valve implantation (VIV-TAVI) in patients with failed bioprostheses remains unclear. The purpose of this study was to assess the prognostic impact of residual moderate MR following VIV-TAVI. METHODS: We retrospectively analyzed 127 patients who underwent VIV-TAVI between March 2010 and November 2021. At least moderate MR was observed in 51.2% of patients before the procedure, and MR improved in 42.1% of all patients. Patients with postoperative severe MR, previous mitral valve intervention, and patients who died before postoperative echocardiography were excluded from further analyses. The remaining 114 subjects were divided into two groups according to the degree of postprocedural MR: none-mild MR (73.7%) or moderate MR (26.3%). Propensity score matching yielded 23 pairs for final comparison. RESULTS: No significant differences were found between groups before and after matching in early results. In the matched cohort, survival probabilities at one, three, and five years were 95.7% vs. 87.0%, 85.0% vs. 64.5%, and 85.0% vs. 29.0% in the none-mild MR group vs. moderate MR-group, respectively (log-rank P=0.035). Among survivors, patients with moderate MR had worse functional status according to New York Heart Association (NYHA) class at follow-up (P=0.006). CONCLUSION: MR is common in patients with failed aortic bioprostheses, and improvement in MR-status was observed in over 40% of patients following VIV-TAVI. Residual moderate MR after VIV-TAVI is not associated with worse early outcomes, however, it was associated with increased mortality at five years of follow-up and worse NYHA class among survivors.