Why is this study important?

Many patients with severe mitral regurgitation (MR) are ineligible for surgery and unsuitable for transcatheter edge-to-edge repair (TEER) due to anatomic challenges such as a narrow left ventricular outflow tract (LVOT), large annulus, or mitral annular calcification. The AltaValve System is a novel atrial-fixation transcatheter mitral valve replacement (TMVR) designed to address these unmet needs.

The 1-year results from this Early Feasibility Study demonstrate durable MR reduction, preserved LV function, negligible LVOT obstruction, and a favorable safety profile — supporting advancement to the ATLAS Pivotal Trial.

What question was this study supposed to answer?

Transcatheter treatment options for severe MR remain limited for patients who are high surgical risk and anatomically unsuitable for TEER. LVOT obstruction, large annular dimensions, and mitral annular calcification are common barriers to existing TMVR platforms. The AltaValve System uses a unique atrial fixation mechanism intended to avoid LVOT compromise and accommodate a broader range of anatomies.

This Early Feasibility Study sought to evaluate the safety, hemodynamic performance, and durability of the AltaValve System at 1 year in this challenging patient population, using both transapical and transseptal delivery approaches.

What did the study show?

• Technical success and MR reduction were achieved in 97% of cases (N=30), with 95% of patients maintaining MR ≤1+ and NYHA Class I/II at 1 year.
• Hemodynamic performance was favorable at 1 year: mean mitral gradient was 4.0 mmHg, and LVOT gradient was only 1.8 mmHg, confirming minimal LVOT interference with the atrial fixation design.
• LVEF was preserved (53% at 1 year vs. 54% at baseline), and functional capacity improved with an average 6-minute walk distance increase of 43 meters.
• The safety profile was notable for the absence of stroke, device embolization, new atrial fibrillation, life-threatening bleeding, or new pacemaker implantation. One patient developed HALT and thrombus attributed to non-adherence to medical therapy.
• Both transapical (n=13) and transseptal (n=17) delivery approaches were used successfully, with the transseptal route representing the majority of cases.
• These results support the durability and safety of the AltaValve System and are now being further validated in the statistically powered ATLAS Pivotal Trial.