Abstract 15663: Trasapical Mitral Valve and Left Ventricular Reshaping to Repair Functional Mitral Regurgitation in a Dilated Ventricle

Abstract

Background: The COAPT trial demonstrated that repair of functional mitral regurgitation (FMR) in heart failure (HF) improves prognosis, only when the LV end diastolic diameter is <65mm. A significant need exists for a new therapy that can address both FMR and the LV in patients with LV EDD>65mm. In this study, we report a novel beating heart transapical device that can address FMR by beating heart papillary muscle approximation (PMA), and reduces the LV size and sphericity as well. Preclinical efficacy of this novel device in a swine HF/FMR model is reported. Methods: The device was prototyped using biocompatible 3D printed parts (Fig A), and a delivery catheter was custom designed for beating heart deployment (Fig B). In 7 healthy pigs, and 4 pigs induced with chronic post-myocardial infarction HF, with moderate or greater FMR, the device was implanted via a transapical access. The device was adjusted in steps - (step 1) reduce the inter-PM distance to an extent that FMR is mild or less; and (step 2) reshape the LV to achieve a 30% reduction in LV EDV and 25% reduction in sphericity index (SI). Echocardiography was used to assess mitral valve function and LV geometry, and LV function was assessed with invasive hemodynamics. Pigs were survived thereafter. Results: With this new device, MR was consistently reduced from moderate levels to none/mild. Mitral valve coaptation length increased from 3.49 ± 0.42 to 6.45± 1.13 mm (p=.019) and tenting area decreased from 158.09± 33 to 116.4± 16.7mm 2 (p=.05). LV EDV was reduced from 142.8± 29.6 to 97.5± 19.6ml (p=.025), SI was decreased from 0.67± 0.04 to 0.49± 0.07 (p=.0497) and IPMD was reduced from 23.5± 5.7 to 12.76± 3.0mm (p=.032). The device did not adversely impact cardiac output (6.59± 1.3 to 4.83± 1.6 LPM, p=.067) or E/A wave ratio (1.40± 0.23 to 1.35±0.29, p=.60). Conclusion: This novel transapical beating heart MV and LV reshaping device, significantly reduced FMR and reshaped the LV in this swine model.