For patients suffering from mitral regurgitation, every advancement in effective treatment means a redefinition of quality of life. On December 4, 2025, the one-year follow-up results from an early feasibility study (EFS) on the AltaValve system were officially released, bringing exciting news to the field of transcatheter mitral valve replacement (TMVR).

This research was presented by Dr. Vlasis Ninios from the Mediterranean Hospital of Thessaloniki, Greece, during the Late Breaking Trial session at the PCR London Valves conference held from November 16-18 in London, UK. The core conclusion is clear: The new supra-annular TMVR system, AltaValve, not only overcomes many limitations of existing technologies but also delivers sustained clinical benefits for patients over one year, offering hope especially to many patients who were previously ineligible for surgery.

Addressing the "Critical Shortcomings" of Existing TMVR, AltaValve Provides Precise Solutions

Many people may not be aware of the technical challenges in mitral valve replacement. In his presentation, Dr. Ninios specifically highlighted a major limitation—"Achilles' heel"—of existing TMVR technology: left ventricular outflow tract (LVOT) obstruction. This is a primary reason many patients fail pre-operative screening and cannot receive treatment. Additionally, issues like mitral annulus size and mitral annular calcification (MAC) also exclude numerous patients.

The core innovation of the AltaValve system lies in its targeted solutions to these pain points. Utilizing an atrial fixation design, it positions the prosthetic valve above the native mitral valve. This not only minimizes the risk of LVOT obstruction but also adapts to different annulus sizes, covering a broader spectrum of patients with mitral regurgitation (MR). Simply put, this device acts like a precisely "tailor-made" component for the heart valve, offering not only better adaptability but also reducing interference with other cardiac structures.

AltaValve^™ System: Redefining TMVR Treatment

4C Medical's core competitiveness stems from its independently developed AltaValve^™ system—a globally pioneering "atrial-only fixation" transcatheter mitral valve replacement (TMVR) device, and currently the only fully retrievable, low-profile transseptal TMVR system. This product addresses numerous pain points of traditional TMVR with three key advantages:

Expanding the Treatable Patient Population: Conventional TMVR is often limited by the degree of mitral annular calcification (MAC) or complex anatomy, excluding many high-risk patients. The AltaValve^™ uses a unique supra-annular positioning design, eliminating the need to replace the native mitral valve. It effectively adapts to patients with moderate/severe MAC and complex anatomy, significantly broadening the treatment scope.

Simplifying the Procedure and Enhancing Safety: Delivered via a transseptal approach and employing an "atrial-only fixation" mode, the system minimizes interference with critical left ventricular structures (such as chordae tendineae and the LVOT), significantly reducing the risk of procedural complications. Its low-profile, fully retrievable delivery system enables precise positioning and deployment, improving procedural success rates.

Preserving Native Cardiac Structure: Unlike traditional valve replacement, the AltaValve^™ does not require removal of the native mitral valve, preserving the mitral annulus and left ventricular function, thereby offering better protection for patients' long-term cardiac health. Early clinical trials show that most patients achieve complete elimination of mitral regurgitation within 30 days post-procedure.

Simple Procedure, Surprisingly Broad Patient Compatibility

Beyond its design advantages, the AltaValve procedure is also highly notable. Using a transseptal approach, the prosthetic valve consists of a nitinol stent frame housing a 27mm bovine pericardial tissue valve. Dr. Ninios described the implantation process as a "simple, straightforward single-step procedure": navigating via a steerable guidewire into the left atrium, curving to align with the mitral valve, and completing implantation from the annulus level towards the atrial roof. The entire process is adjustable and retrievable, greatly enhancing safety and precision.

Even more noteworthy is its broad compatibility. Study data show an anatomical acceptance rate of 77% for AltaValve. Among the 30 enrolled patients, over half (53%) had been rejected by other technologies due to LVOT stenosis risk, 27% had large annuli (>48mm), and 23% had moderate/severe MAC—all traditionally considered "contraindicated populations" for conventional TMVR, yet they found opportunity with AltaValve.

Impressive One-Year Follow-up Data: Safe, Effective, Sustained Benefits

Ultimately, clinical data measure the core value of a medical technology. This multi-center study across Europe, the US, and Japan enrolled patients at high surgical risk with symptomatic severe MR. 63% were female, with functional and degenerative MR patients equally represented. Initially, 13 patients were treated via a transapical approach, but the protocol has since shifted entirely to the less invasive transseptal approach (used in 17 patients in this study).

One-year follow-up results show a procedural technical success rate as high as 97%, with only one patient converted to surgery. Crucially, mitral regurgitation was completely eliminated in all patients. The mean mitral valve gradient decreased from a baseline of 2.5 mmHg to 2.1 mmHg post-procedure, indicating significant hemodynamic improvement. CT analysis also revealed that after AltaValve implantation, the neo-LVOT area increased by approximately 0.8 cm², and the valve annulus moved away from the LVOT during systole, effectively protecting native mitral valve function.

Safety outcomes were also excellent: one-year all-cause mortality was 17% in the transapical group but only 7% in the transseptal group. Cardiac mortality was 0% in the transseptal group. In the entire cohort, only one patient developed valve thrombosis due to non-compliance with medication, and one patient required a pacemaker. There were no incidents of stroke, new-onset atrial fibrillation, or mitral valve re-intervention. At one year, 96% of patients improved to NYHA functional class I or II, indicating a substantial enhancement in quality of life.

A Promising Future: Five-Year Follow-up and ATLAS Pivotal Trial Advancement

Dr. Ninios also mentioned a recent study published in JACC: Advances (led by Dr. Nadira Hamid of the Minneapolis Heart Institute, USA) showing that after AltaValve implantation, patients exhibited reverse remodeling with reduced left atrial volume and improved left atrial strain. This correlates with sustained improvements in NYHA class, Kansas City Cardiomyopathy Questionnaire (KCCQ) scores, and six-minute walk test results, further supporting its long-term benefit potential.

Currently, follow-up for this EFS will continue for five years. Concurrently, the ATLAS pivotal trial for AltaValve has begun enrolling patients in the US and Europe, aiming to include 100 MAC patients and up to 350 patients in the main cohort. "The one-year follow-up results demonstrate its sustained clinical benefits," Dr. Ninios concluded. "The TMVR field has faced many challenges for years. We hope the ATLAS trial will help us overcome these hurdles and bring hope to more patients."

About 4C Medical Technologies

Founded in 2015 and headquartered in Maple Grove, Minnesota, USA, 4C Medical Technologies is a medical device company focused on developing innovative, minimally invasive therapies for structural heart disease. With a core team boasting deep experience in the cardiovascular medical field, the company accurately identifies clinical pain points. It remains dedicated to R&D for interventional treatment solutions for mitral regurgitation (MR) and tricuspid regurgitation (TR), committed to breaking through traditional treatment bottlenecks through technological innovation, enabling more patients to benefit from safe and effective minimally invasive treatments.