Author + information
- Georg Lutter, MD, PhD,
- Lucian Lozonschi, MD∗ (, )
- Adrian Ebner, MD,
- Santiago Gallo, MD,
- Christian Marin y Kall, MD,
- Emil Missov, MD, PhD and
- Eduardo de Marchena, MD
- ↵∗Division of Cardiothoracic Surgery, University of Wisconsin School of Medicine, H4/348 CSC, 600 Highland Avenue, Madison, Wisconsin 53792
Transcatheter mitral valve replacement (TMVR) faces significant challenges arising from the heterogeneous pathology of the mitral valve and the anatomic complexity of the mitral annulus, leaflets, and subvalvular apparatus (1,2). The Tendyne mitral prosthesis (Tendyne Holdings, Roseville, Minnesota) is a fully retrievable, apically tethered trileaflet porcine pericardial valve sewn onto a nitinol frame (Figure 1). U.S. Food and Drug Administration Export Permit and international regulatory approvals were obtained before the study. The protocol was approved by the National Ethics Committee of Paraguay. Informed consent was obtained from 2 patients with severe mitral regurgitation (MR). The patients agreed to have the Tendyne valve implanted and observed for up to 2 h before proceeding with conventional mitral valve surgery.
On February 19, 2013, TMVR was performed in a 57-year-old man with severe MR secondary to degenerative mitral valve disease. At a later date, TMVR was also performed in a 55-year-old woman with severe MR and combined rheumatic and degenerative disease. In both patients, a Tendyne valve was deployed through a left mini-thoracotomy of <5 cm and a transapical approach. A sternotomy was performed before TMVR in the first patient only, and a direct left atrial pressure monitoring line was also inserted. Echocardiographic and angiographic MR was reduced from grade 4 to grade 0 in the first patient (Figures 2A to 2C) and from grade 4 to grade 1 in the second patient (Figures 2D to 2F) after deployment of the prosthesis. The direct left atrial pressure decreased from a mean of 49 to 19 mm Hg in the first patient. The mean pulmonary capillary wedge pressure (PCWP) decreased in the second patient from 44 to 15 mm Hg. The giant V-wave of MR on the initial PCWP tracing was completely effaced after deployment of the prosthesis in both patients (Figure 3). The first patient had no central or paravalvular regurgitation at normal arterial pressure and with systolic blood pressure challenge up to 170 mm Hg intraoperatively. His thermodilution cardiac output remained relatively unchanged after deployment 3.7 versus 3.6 l/min before TMVR. In the second patient, it was not possible to draw the prosthesis from the supra-annular position into the mitral orifice using the intended method of tether traction alone. Therefore, the device was recaptured and deployed inside the mitral annulus. However, this position did not allow for complete expansion of the Tendyne prosthesis and resulted in mild paravalvular regurgitation (Figures 4A to 4C). Despite the +1 paravalvular leak, both the thermodilution cardiac output and mixed venous O2 saturation increased after Tendyne valve deployment (3.03 to 5.0 l/min and 32% to 64%, respectively). After completion of the protocol, both patients underwent conventional mitral valve replacement surgery during which the Tendyne prostheses were explanted without noting any damage to the mitral valve annulus, leaflets, or subvalvular apparatus from the transcatheter procedure. Both patients tolerated the procedures well and had an uneventful post-operative course and recovery.
This first acute human study shows the Tendyne mitral prosthesis can be safely deployed off-pump using a transapical approach. The apical tether and the frame design allowed for acute reduction of severe MR and rapid hemodynamic improvement. These first short-term results with the apically tethered Tendyne mitral prosthesis are encouraging and support the next-phase studies.
Please note: This study was supported by Tendyne Holdings, Inc. Drs. Lutter, Lozonschi, and de Marchena own intellectual property and stock in Tendyne Holdings; and have received consulting fees from Tendyne Holdings. Dr. Ebner and Dr. Missov have received consulting fees and research funds from Tendyne Holdings. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose. Drs. Lutter and Lozonschi have contributed equally to this work.
- American College of Cardiology Foundation