Comparison of Two Generations of Self-Expandable Transcatheter Heart Valves in Nine Surgical Valves: An In Vitro Study

(1) Background: This study aimed to analyse the hydrodynamic performance of two generations of self-expanding transcatheter heart valves (THV) as a valve-in-valve (ViV) in different surgical aortic valve (SAV) models under standardised conditions. The nitinol-based Evolut R valve is frequently used in ViV procedures. It is unclear whether its successor, the Evolut PRO, is superior in ViV procedures, particularly considering the previously implanted SAV model. (2) Methods: EvolutTM R 26 mm and EvolutTM PRO 26 mm prostheses were implanted in nine 21 mm labelled size SAV models (Hancock® II, Mosaic® UltraTM, EpicTM Supra, TrifectaTM GT, Perimount®, Perimount® Magna Ease, AvalusTM, IntuityTM, Freestyle®) to analyse their hydrodynamic performance under defined circulatory conditions in a pulse duplicator. (3) Results: Both THVs presented with the lowest effective orifice area (EOA) and highest mean pressure gradient (MPG) inside Hancock® II, whereas THVs in Intuity showed the highest EOA and lowest MPG. Evolut R and Evolut PRO showed significant hydrodynamic differences depending on the SAV. Both THVs performed similarly in porcine valves. Although the Evolut R performed better than Evolut PRO in stented bovine SAVs, the Evolut PRO was superior inside the Intuity. Further, the SAV model design markedly influenced the TAV's geometric orifice area and pin-wheeling index. (4) Conclusions: These findings show that the Evolut R and Evolut PRO perform differently depending on the previously implanted SAV model. THV selection for treatment of a specific SAV model should consider these results.

Impact of Different Valve-in-Valve Positions on Functional Results of the New Generation of Balloon-Expandable Transcatheter Heart Valve

OBJECTIVES

 Very precise positioning of the transcatheter heart valve (THV) inside the degenerated SAV is a crucial factor for valve-in-valve (ViV) procedure to achieve optimal hemodynamic results. Therefore, our study aimed to investigate the impact of implantation depth on functional results after ViV procedures in a standardized in vitro setting.

METHODS

 THV (SAPIEN 3 Ultra 23-mm size) and three SAV models (Magna Ease, Trifecta, and Hancock II-all 21-mm size) were tested at different circulatory conditions in five different positions of the THV (2-6 mm) inside the SAV. Mean pressure gradient (MPG), effective orifice area (EOA), geometric orifice area (GOAmax), and pinwheeling index (PWImean) were analyzed.

RESULTS

 EOA and MPG of the THV did not differ significantly regarding the position inside the Magna Ease and the Hancock II (p > 0.05). However, EOA differed significantly, depending on the position of the THV inside Trifecta (2 vs. 5 mm; p = 0.021 and 2 vs. 6 mm; p < 0.001). The THV presented the highest EOA (2.047 cm2) and the lowest MPG (5.387 mm Hg) inside the Magna Ease, whereas the lowest EOA (1.335 cm2) and the highest MPG (11.876 mm Hg) were shown inside the Hancock II. Additionally, the highest GOAmax and the lowest PWImean of the THV were noticed inside the Magna Ease. The THV showed lower GOAmax and higher PWImean inside the Trifecta when placed in a deeper position.

CONCLUSION

 Deep implantation of the SAPIEN 3 Ultra inside the Trifecta correlates with impaired functional results. In contrast, the implantation position of the SAPIEN 3 Ultra inside the Magna Ease and the Hancock II did not have a significant effect on functional results.

Impact of high-pressure balloon aortic valvuloplasty on the hydrodynamic result after a transcatheter valve-in-valve procedure

OBJECTIVES

The aim of this study was to investigate the degree of functional improvement of a transcatheter heart valve (THV) for valve-in-valve after bioprosthetic valve fracture (BVF) of three small surgical aortic valve bioprostheses (SAVBP) using high-pressure balloon aortic valvuloplasty (HP-BAV) under standardized ex-vivo-conditions.

METHODS

A THV 26 mm (Evolut R) and SAVBP 21 mm (Perimount Magna Ease, Trifecta, and Epic supra [n = 4] were used. Mean pressure gradient (MPG), effective orifice area (EOA), geometric orifice area (GOA), minimal internal diameter (MID), and pinwheeling index (PWI) were analyzed before and after HP-BAV of the SAVBP using a noncompliant balloon. Fracturing of the SAVBP was done before implantation of the THV and the balloon pressures at the point of fracture were recorded.

RESULTS

The Magna Ease and Epic fractured at balloon pressures of 18 and 8 atm, respectively. The Trifecta did not fracture up to a balloon pressure of 30 atm but was dilated. HP-BAV led to increased THV expansion as evident by straightened coaptation lines of the Evolut R 26 mm with reduced PWI, increased MID, and increased GOA in all 21 mm SAVBP. Evolut R showed significantly lower MPG and higher EOA as ViV in all prostheses after HP-BAV (p < 0.001). MPG and EOA of Evolut R differed regarding the SAVBP. Evolut R presented the lowest MPG and highest EOA in Magna Ease and the highest MPG and lowest EOA in Epic supra.

CONCLUSIONS

The degree of function improvement of the same THV as ViV after HP-BAV depends on the surgical valve model. Functional improvement can also be achieved without valve fracture.