This is a prospective, single arm, multicenter, clinical trial designed to evaluate the safety and performance of the AltaValve System for the treatment of mitral regurgitation in a targeted patient population.

Inclusion Criteria:

• Age ≥ 18 years.
• Symptomatic New York Heart Association (NYHA) class II-IV.
• Moderate-to-severe or severe MR (3+) despite optimal guideline-directed medical therapy (GDMT) as determined by an independent Echo Core Lab.
• Unsuitable for surgery and Transcatheter Edge-toEdge Repair (TEER) as determined by the local site Heart Team.

Exclusion Criteria (Abbreviated List):

• Inability to understand the trial or a history of non-compliance with medical advice.
• Inability to provide signed Informed Consent Form (ICF).
• History of any cognitive or mental health status that would interfere with participation in the trial.
• Currently enrolled in any other pre-approval investigational trial (does not apply to long-term post-market trials unless these trials might clinically interfere with the current trial endpoints (e.g., limit use of trial-required medication, etc.)).
• Female subjects who are pregnant or planning to become pregnant within the trial period.
• Known hypersensitivity or contraindication to heparin, or warfarin without adequate alternative medications.
• Known hypersensitivity to nitinol (i.e., nickel allergy) that cannot be adequately medicated.
• Known hypersensitivity to contrast media that cannot be adequately medicated.
• Evidence of current left ventricular ejection fraction (LVEF) ≤ 25%.
• Concurrent medical condition with a life expectancy of less than 12 months.
• Transcatheter aortic repair or replacement within 90 days prior to the index procedure.
• Percutaneous coronary intervention (PCI) within 90 days prior to the index procedure.