569 TIARA - a Novel Catheter-Based Mitral Valve Bio-Prosthesis: Initial Experiments and Pre-Clinical Results

Abstract

A significant proportion of patients with severe mitral regurgitation (MR), have severe comorbidities and are not candidates for conventional surgery because of high operative risk. The field of percutaneous mitral valve (MV) repair is developing and many technologies are now under investigation. To date, trans-catheter valve implantation is limited to pulmonary and aortic valves. The present study seek to assess the safety and feasibility of minimally invasive trans-catheter implantation of a novel self-expanding MV specifically designed for the unique complex anatomical configuration of the mitral apparatus - the TIARA self-expanding bioprosthetic valve. Using a trans-apical approach, the TIARA valve were implanted in domestic swine with fluoroscopic and 3D transesophageal echocardiographic (TEE) guidance. Follow-up varied from 90 minutes to 96 hours. The valves were delivered using a short flexible 26-30F delivery catheter. TIARA valves were successfully implanted in 29/36 (81%) of the attempted animals. Total procedure time ranged from 17 to 26 minutes, and the prosthesis deployment time ranged from 5 to 13 minutes. In the 29 successful implantations, TEE demonstrated excellent function and alignment of the TIARA prosthesis, with no left ventricular outflow tract obstruction, no pericardial effusion or encroachment on the aortic valve, and no trans-prosthesis gradients. Significant paravalvular leaks were only seen in cases of either MV annulus-prosthesis mismatch or failed implantation. Macroscopic evaluation of the explanted hearts demonstrated stable and secure positioning of the valves in all planes of the mitral apparatus with no evidence of injuries to the ventricular or atrial walls. We report our successful initial pre-clinical experience with the TIARA trans-catheter self-expanding mitral bioprosthetic valve. Implantation of the TIARA valves is technically feasible and safe, and results in a stable and well-functioning mitral valve bioprosthesis.