Development and Hydrodynamic Assessment of a Novel Transcatheter Mitral Valve

Mitral regurgitation (MR) is one of the most common mitral valve disorders and, if untreated, may lead to heart failure. As its prevalence increases with age, a significant proportion of symptomatic patients are currently declined for surgery because judged high risk, and their number is expected to rise significantly in the future. Transcatheter valve implantation, already largely adopted for the treatment of calcific aortic valves, could represent an effective solution for those high-risk patients. However, currently available transcatheter valve devices are unsuitable for the mitral position. Here, we present a novel heart valve suitable for transcatheter mitral implantation. The device consists of a self expanding nitinol wireframe, supporting two tissue leaflets, a sealing cuff to reduce paravalvular leakage and a polymeric skirt gently distributing the anchoring force over the annulus. The wireframe is made of superelastic NiTi alloy, and is optimised to provide adequate matching to the mitral valve anatomy, while minimising the stresses during loading in the delivery system. Leaflets are made from glutaraldehyde fixed xenograft pericardium, and are designed to minimise the stress during systole and provide sufficient length to ensure proper coaptation at different geometries of the host annulus. Prototypes of the device were successfully manufactured, and assessed in-vitro, on a hydro-mechanical pulse duplicator. Tests were performed at 70 beats per minute, cardiac output of 5 L/min and mean arterial pressure equal to 100 mmHg, using mock mitral valve holders of sizes ranging from 20 to 26 mm (inter-trigonal). Tests confirmed a good anchoring of the valve, and meeting of the hydrodynamic requirements in the international standard ISO5840:2015-3. Preliminary results indicate that the proposed device could represent a valid alternative for the treatments of MR, more suitable for current and future patients’ population.