Reshaping the Ventricle From Within: MIRTH (Myocardial Intramural Remodeling by Transvenous Tether) Ventriculoplasty in Swine.

MIRTH (Myocardial Intramural Remodeling by Transvenous Tether) is a transcatheter ventricular remodeling procedure. A transvenous tension element is placed within the walls of the beating left ventricle and shortened to narrow chamber dimensions. MIRTH uses 2 new techniques: controlled intramyocardial guidewire navigation and EDEN (Electrocardiographic Radial Depth Navigation). MIRTH caused a sustained reduction in chamber dimensions in healthy swine. Midventricular implants approximated papillary muscles. MIRTH shortening improved myocardial contractility in cardiomyopathy in a dose-dependent manner up to a threshold beyond which additional shortening reduced performance. MIRTH may help treat dilated cardiomyopathy. Clinical investigation is warranted.
Competing Interests: This work was supported by the Division of Intramural Research, National Heart Lung and Blood Institute, National Institutes of Health USA (grant Z01-HL006040 to Dr Lederman). Drs Bruce and Lederman are coinventors on patents, assigned to National Institutes of Health, on MIRTH-related devices. Dr Rogers is a consultant and physician proctor for Edwards Lifesciences and Medtronic; is a Medtronic advisory board member; and has an equity interest in Transmural Systems. Drs Babaliaros and Greenbaum receive institutional research support from Abbott Vascular, Ancora Heart, Edwards Lifesciences, Gore Medical, Jena Valve, Medtronic, Polares Medical, Transmural Systems, and 4C Medical; receive consulting fees from Abbott Vascular, Edwards Lifesciences, and Medtronic; and have equity interest in Transmural Systems. Drs Campbell-Washburn, Herzka, and Lederman are investigators on a U.S. Government Cooperative Research and Development Agreement with Siemens. Siemens participated in the modification of the MRI system from 1.5-T to 0.55-T and provided investigational intracardiac echocardiography devices. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.