Valve-in-valve transcatheter transfemoral mitral valve implantation (ViV-TMVI): Characteristics and early results from nationwide registry.

BACKGROUND: Valve-in-valve transcatheter transfemoral mitral valve implantation (ViV-TMVI) is an emerging treatment alternative to reoperation in high surgical risk patients with a failed mitral bioprostheses.

AIM: To describe characteristics and evaluate 30-day outcomes of ViV-TMVI in the Polish population.

METHODS: Nationwide registry was initiated to collect data of all patients with failed mitral bioprosthesis undergoing ViV-TMVI in Poland. This study presents 30-days clinical and echocardiographic follow-up.

RESULTS: Overall, 27 ViV-TMVI were performed in 8 centers until May 2022 (85% since 2020). Mean (standard deviation [SD]) age was 73 (11.6) years with the median (interquartile range [IQR]) STS score of 5.3% (4.3%-14.3%). Mean (SD) time between surgical implantation and ViV-TMVI was 8.2 (3.2) years. Failed Hancock II (29%) and Perimount Magna (22%) were most frequently treated. Mechanisms of failure were equally often pure mitral regurgitation or stenosis (both 37%) with mixed etiology in 26%. Balloon-expandable Sapien 3/Ultra were used in all but 1 patient. Technical success was 96.3% (1 patient required additional prosthesis). Mean (SD) transvalvular mitral gradient reached 6.7 (2.2) mm Hg and mitral valve area was 1.8 (0.4) cm². None of the patients had moderate or severe mitral regurgitation with only 14.8% graded as mild. In 92.6% device success (2 patients had mean gradient ≥10 mm Hg) and in 85.6% procedural success was present. There were no deaths, cerebrovascular events or need for mitral valve surgery during 30-day follow-up.

CONCLUSIONS: In short-term observation ViV-TMVI is safe and effective alternative for patients with failed mitral bioprosthesis at high surgical risk of re-operation. Longer observations on larger sample are warranted.