Results of the early feasibility study evaluating outcomes of the AltaValve (4C Medical) sub-valvular transcatheter mitral valve replacement (TMVR) system indicate that the device may be effective at reducing mitral regurgitation (MR) with a lessened risk of left ventricular outflow tract (LVOT) obstruction.
Vlasis Ninios (Interbalkan Medical Center, Thessaloniki, Greece) presented results from the trial at the 2024 Cardiovascular Research Technologies (CRT) meeting (9–12 March, Washington, DC, USA).
Limitations with current sub-valvular TMVR technologies include high screen failure rates, in particular due to the increased risk of LVOT obstruction, Ninios detailed, noting that the AltaValve system is designed to treat a broad population of mitral regurgitation (MR) patients and minimise the risk of LVOT obstruction.
The device, which is currently limited to investigational use only, is a transseptal TMVR system with AltaValve’s prosthetic valve positioned above the native mitral valve via an atrial-only fixation that is intended to ensure that cardiac structures are retained within the left ventricle. The AltaValve is also designed in a way that allows future left atrial access for other procedures.
The prospective, multicentre, single-arm early feasibility study enrolled 24 patients with severe MR who were considered high risk for mortality and morbidity with surgery. Ninios reported that all patients had severe MR, with 33% classified as having degenerative or mix MR, and 67% functional MR.
Additionally, Ninios reported that left ventricular function was preserved in most patients (ejection fraction, 53.0±6.4%), whilst 79% of subjects were New York Heart Association (NYHA) class III/IV at baseline.
Technical success was reported in 96% of cases, whilst relief of MR was complete with no patient having mitral regurgitation, including no paravalvular leak (PVL).
Post-procedure mean mitral valve gradient was 2.2±1.1mmHg and left ventricular ejection fraction (LVEF) was unchanged. At 30-day follow-up, 95% of subjects had none /trace PVL, with one other patient having mild PVL.
NYHA assessment at the 30-day follow-up marker showed 96% of subjects as having improved to class I/II. No patient had thrombus, embolisation, erosion, new onset of atrial fibrillation or need for pacemaker placement.
The findings led Ninios to conclude that outcomes with AltaValve TMVR a clinically significant reduction in MR, sustained implant performance, and notable improvements in NYHA class. “The atrial-fixation TMVR technology of AltaValve may help reduce risk of LVOT obstruction and increase patient eligibility,” Ninios reported.
A large pivotal study is being designed to further assess longer term safety and performance of AltaValve system.
