Objectives: The mitral valve-in-valve (ViV) procedure is increasingly used in inoperable patients. This procedure evades surgical risks but is associated with other complications. The aim of this study was to investigate hemodynamically relevant effects such as left ventricular outflow tract (LVOT) obstruction and paravalvular leakage in commonly used ViV combination.
Methods: The hemodynamic investigation of a total of 60 combinations of transcatheter valves Sapien III (SIII) in three sizes (23, 26, and 29 mm) and five heart valves in four sizes each (Hancock II, Mosaic, Medtronic; Epic, St. Jude Medical; Perimount, Edwards; Pericarbon More, LivaNova, 25–31 mm) was performed in a pulse duplicator. The ViV combinations were then implanted in an extracorporeal beating porcine heart model for further measurements. The transvalvular pressure gradients (TVG), paravalvular leakage volumes (PVL), and regurgitation fraction (RF) were measured. Echocardiographic and endoscopic examinations were performed.
Results: Most ViV combinations are associated with a worsening of valve hemodynamics. This means that either mean RF or mean TVG is significantly higher (p < 0.001). SIII 23 mm fits in only a few small valves without significant PVL and shows high TVG as expected. For the valve sizes ≥ 29 mm, only a combination with SIII 29 mm is possible without valve deformity and significant PVL with a variation of acceptable to moderately elevated TVG. SIII 26 in medium-sized valves should be selected with caution, considering the risk for PVL or high TVG. Echocardiographic results showed that the smaller the LVOT diameter before SIII implantation and the larger the implanted SIII is, the higher the measured flow velocity over LVOT and aortic valves (p < 0.001) become.
Conclusion: The selection of the appropriate SIII varies depending on the orifice area in different valve models. With proper selection of the SIII, ViV is a suitable method for inoperable patients. The use of small SIII can lead to increased TVG and PVL. Imaging modalities to check for sufficient LVOT space is required prior to implantation.
