Early Experience With New Transcatheter Mitral Valve Replacement

Study Questions:

What are the early outcomes associated with transcatheter mitral valve replacement (TMVR) using the new Intrepid TMVR system?


The Intrepid TMVR system includes a self-expanding, nitinol valve with bovine pericardial leaflets; and a transapical (35 Fr sheath) delivery system. Patients with symptomatic severe mitral regurgitation (MR) with no or minimal valve calcification and left ventricular ejection fraction (LVEF) >20% who were deemed high or extreme risk by local heart teams were enrolled in a global pilot study at 14 sites in the United States, Australia, and Europe.


A total of 50 consecutively enrolled patients (mean age 73 ± 9 years, 58.0% men, 84% secondary MR) underwent TMVR with the valve. The mean Society of Thoracic Surgeons (STS) score was 6.4 ± 5.5%; 86% of patients were New York Heart Association (NYHA) class III or IV, and the mean LVEF was 43 ± 12%. Device implant was successful in 48 patients, with a median deployment time of 14 (interquartile range [IQR] 12, 17) minutes. The 30-day mortality was 14%, with no disabling strokes or repeat interventions. Median follow-up was 173 (IQR 54, 342) days. At latest follow-up, echocardiography confirmed mild or no residual MR in all implanted patients. Improvements in symptom class (79% in NYHA I or II at follow-up, p < 0.0001 vs. baseline), and Minnesota Heart Failure Questionnaire scores (56.2 ± 26.8 vs. 31.7 ± 22.1, p = 0.011) were observed.


TMVR with the Intrepid valve system was feasible in a population at high- or extreme-risk for conventional MVR. The authors concluded that these results could help inform trial design of TMVR in lower-risk patients with severe MV regurgitation.


Transcatheter aortic valve replacement (TAVR) is established as a standard of care among intermediate- and higher-risk patients with severe, symptomatic aortic stenosis. In contrast, TMVR is an emerging therapy with no device currently approved for clinical use in the United States. Challenges in performing TMVR compared to TAVR include those related to access, and the unique geometry of the MV (including a noncircular, nonplanar, and nonrigid annulus). This pilot study of a new, self-expanding nitinol valve in 50 patients at high or extreme surgical risk found successful implantation in 96% of patients, a short and reproducible procedure with a minimal learning curve, reduction of MR to mild or none in all implanted patients, no device malfunction during limited (median 173 days) follow-up, and symptomatic and quality-of-life improvement among survivors.

Clinical Topics: Cardiac Surgery, Heart Failure and Cardiomyopathies, Invasive Cardiovascular Angiography and Intervention, Noninvasive Imaging, Valvular Heart Disease, Aortic Surgery, Cardiac Surgery and Heart Failure, Cardiac Surgery and VHD, Acute Heart Failure, Interventions and Imaging, Interventions and Structural Heart Disease, Angiography, Echocardiography/Ultrasound, Nuclear Imaging, Mitral Regurgitation

Keywords: Aortic Valve Stenosis, Cardiac Surgical Procedures, Echocardiography, Heart Failure, Heart Valve Diseases, Mitral Valve, Mitral Valve Insufficiency, Quality of Life, Standard of Care, Stroke, Stroke Volume, Transcatheter Aortic Valve Replacement, Angiography

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