Self-expandable transcatheter valve is a potentially useful option for a failing small surgical aortic bioprosthetic valve.

Objective: Trans-catheter aortic valve implantation inside a failing surgical aortic valve bio-prosthesis has become an alternative for patients at high risk for redo surgical aortic valve replacement. However, the correlation between the size of the failing surgical aortic valve and the occurrence of prosthesis-patient mismatch after trans-catheter implantation is still controversial. The aim of this study is to analyze and report the results in Japanese patients.

Methods: Thirty patients who underwent trans-catheter aortic valve implantation inside a failing surgical aortic valve at our hospital were retrospectively reviewed with results from echocardiography and computed tomography.

Results: The patients' mean age was 84.5 ± 4.8 years. The mean body surface area was 1.42 ± 0.13 m². The cohort was divided into two groups according to the size of the failing bio-prosthesis: small (≦19 mm) and large (> 19 mm). There were no significant differences in mean pressure gradient (12.2 ± 4.0 mmHg vs. 11.1 ± 1.2 mmHg; p = 0.54) and effective orifice area index (1.00 ± 0.26 cm²/m² vs. 0.99 ± 0.25 cm²/m²; p = 0.92) between the groups at 6 months after trans-catheter implantation. The incidence of moderate (38.5% vs. 28.6%; p = 0.59) and severe (0% vs. 7.1%; p = 0.33) prosthesis-patient mismatch was equivalent. There was no significant difference in survival between the two groups (log-rank test p-value = 0.08).

Conclusions: Trans-catheter implantation inside a failing small aortic valve did not increase the frequency of prosthesis-patient mismatch in this Japanese cohort.