EFS of Posterior Leaflet Replacement to Reduce Mitral Regurgitation (United States)

Inclusion Criteria: 1. Patient has symptomatic moderate-to-severe to severe functional mitral regurgitation despite stable doses of maximally tolerated guideline directed medical therapy (GDMT) per the Local Heart Team. Note: In the 30 days prior to performing screening assessments, no new GDMT medications should be introduced and current doses should be stable (i.e. no decrease of \> 50% or increase of \> 100%) excluding diuretics. Any changes beyond this range would not be considered stable GDMT. 2. Functional MR graded 3+ or higher (using a scale of 0 to 4+) by transthoracic echocardiography (TTE) within 60 days prior to study procedure as evaluated by the sponsor's Echo Core Lab. 3. New York Heart Association (NYHA) Functional Class II, III or ambulatory IV heart failure 4. Patient must present with an STS Score less than 10% and deemed by the Local Heart Team to be at high risk but operable for mitral valve surgery. 5. The Local Heart Team deems the patient unsuitable for commercially approved transcatheter mitral valve therapies 6. 21 years of age or older 7. Native mitral valve geometry and size is compatible with the Polares MRace system 8. Anatomy is suitable for transfemoral transseptal access with the Polares MRace system 9. Patient is willing to participate in study and provides signed IRB/EC-approved informed consent 10. Treating physician and patient agree that patient is able to return for all required post-procedure follow-up visits 11. Patient is approved by an independent Patient Eligibility Committee Exclusion Criteria: 1. Echocardiographic parameters (any of the following, assessed by the Echo Core Lab) 1. Left ventricular ejection fraction (LVEF) \< 30% 2. Pulmonary artery systolic pressure (PASP) \> 70mmHg or \> 2/3 SBP (Systolic Blood Pressure) 3. Left Ventricle End Diastolic Volume (LV EDV) \> 200 mL 4. Left Ventricle End Systolic Volume (LV ESV) \> 140 mL 5. Left Ventricle End Diastolic Diameter (LV EDD) \> 70 mm 6. Left Ventricle End Systolic Diameter (LV ESD) \> 55 mm 2. Severe Right Ventricle (RV) dysfunction as per assessment by Local Heart Team or Eligibility Committee . 3. Severe tricuspid regurgitation. 4. Severe aortic stenosis or insufficiency. 5. Severe mitral annulus calcification. 6. Diseased mitral anterior and/or posterior leaflet, such as flail, / prolapse, or/ heavy moderate to severe calcification. 7. Barlow's disease. 8. Presence of an implanted vena cava filter or any other device (e.g. ASD closure device) that may interfere with femoral vein access or delivery system access to the mitral valve. 9. Contraindication for transesophageal echocardiography (TEE) or MDCT scan 10. Active infection or endocarditis or infection requiring antibiotic therapy within 2 weeks of scheduled procedure. 11. Previous mitral valve surgery or transcatheter mitral valve procedure. 12. Prior orthotopic heart transplantation. 13. Evidence of intra-cardiac, inferior vena cava (IVC) or femoral venous thrombus. History of deep vein thrombosis (DVT) or pulmonary embolism within 6 months of the index procedure. 14. Untreated Class I indication for pacing (CRT). Implant or revision of any pacing device \< 30 days prior to intervention 15. Any untreated clinically significant coronary artery disease requiring revascularization. Coronary, carotid, or endovascular artery disease treated percutaneously \< 30 days prior to study procedure. Cardiac surgery \< 90 days prior to study procedure. 16. Myocardial infarction requiring intervention \< 30 days prior to study procedure 17. Infiltrative cardiomyopathies (e.g., amyloidosis, hemochromatosis, sarcoidosis), hypertrophic or restrictive cardiomyopathies, and constrictive pericarditis) 18. Active peptic ulcer or upper gastrointestinal bleeding \< 90 days prior to study procedure. 19. Stroke \< 180 days prior to study procedure. 20. Severe COPD requiring oral steroid therapy or oxygen therapy. 21. Severe renal insufficiency (creatinine \> 3.0 mg/dL) or patient requiring dialysis 22. Cardiogenic shock at time of enrolment. Hemodynamic instability requiring inotropic support or mechanical heart assistance. 23. Concurrent medical condition with a life expectancy of less than 2 years 24. Pregnancy or breastfeeding at time of enrolment with a positive pregnancy test within 14 days of study procedure. 25. History of bleeding diathesis or coagulopathy or leukopenia (WBC \< 3,000 mcL) or acute anemia (Hb \< 9 g/dL) or thrombocytopenia (platelets \< 50,000 cells mcL) 26. Known hypersensitivity or contraindication to aspirin, heparin, ticlopidine or clopidogrel, nitinol, tantalum or allergy to contrast agents that cannot be pre-medicated. Note. Patient must be able to tolerate at least one antiplatelet medication AND one anticoagulant medication. 27. Severe dementia or lack of capacity due to conditions that result in either inability to provide informed consent for the trial/procedure, prevent independent lifestyle outside of a chronic care facility, or will fundamentally complicate rehabilitation from the procedure or compliance with follow-up assessments. 28. Patient is in need for emergent or urgent surgery for any reason or any planned cardiac surgery within the next 12 months. 29. Company employees or their immediate family members. 30. Patient is considered to be part of a vulnerable population, is under guardianship, or subject to any other medical, social or psychological conditions that preclude appropriate consent and follow-up. 31. Patient is participating in another clinical study for which follow-up is currently ongoing.