An Initial Evaluation of the Carillon Mitral Contour System for Treatment of Atrial Function Mitral Regurgitation

Inclusion Criteria: 1. Moderate-to-severe non-primary Mitral Regurgitation (as assessed by qualitative, semi-quantitative and/or quantitative echocardiographic assessment in the setting of all of the following: a. Severe left atrial (LA) dilatation as defined by at least two (2) of the following: i. LA area ≥ 41cm2 ii. Indexed LA volume \> 48mL/m2 iii. LA diameter ≥ 52 mm for men and ≥ 46 mm for women b. Preserved left ventricular contractility (Left Ventricular Ejection Fraction ≥50% by Simpson's biplane technique) c. No more than mild left ventricular dilatation as defined by: i. LV diastolic volume/BSA (mL/m2) \<90 mL/m2 for men and \<71 mL/m2 for women ii. LV systolic volume/BSA (mL/m2) \<39 mL/m2 for men and \<33 mL/m2 for women 2. New York Heart Association (NYHA) Class II, III or ambulatory IV heart failure 3. Stable heart failure medication regimen for at least 30 days prior to index procedure including antihypertensives and/or diuretics to achieve controlled BP (\< 140 mmHg systolic) and adequate heart rate control (\<100 bpm resting HR) 4. Patient deemed appropriate candidate for transcatheter mitral valve repair by the local multidisciplinary heart team 5. Subject meets anatomic screening criteria as determined by angiographic screening at the time of the index procedure to ensure that implant can be sized and placed in accordance with the Instructions for Use 6. Female subjects of child-bearing potential must have a negative serum BHCG test 7. Age ≥ 18 years old 8. The subject has read the informed consent, agrees to comply with the requirements, and has signed the informed consent to participate in the study Exclusion Criteria: 1. Hospitalization in past three (3) months due to myocardial infarction, coronary artery bypass graft surgery, and/or unstable angina 2. Evidence of transient ischemic attack or stroke within three (3) months prior to intervention 3. Percutaneous coronary intervention in the last 30 days 4. Subjects expected to require any cardiac surgery, including surgery for coronary artery disease or for pulmonic, aortic, or tricuspid valve disease within one (1) year 5. Subjects expected to require any percutaneous coronary intervention within 30 days of the index procedure. 6. Pre-existing device (e.g., pacing lead) in coronary sinus (CS) / great cardiac vein (GCV), or anticipated need for cardiac resynchronization therapy (CRT) within twelve (12) months 7. Presence of a coronary artery stent under the CS / GCV in the implant target zone 8. Presence of left atrial appendage (LAA) clot. 9. Presence of primary renal dysfunction or significantly compromised renal function as reflected by a serum creatinine \> 2.2 mg/dL (194.5 µmol/L) OR estimated Glomerular Filtration Rate (eGFR) \< 30 ml/min 10. Poorly controlled atrial fibrillation or flutter, with poor ventricular rate control (\> 100 bpm resting HR), or other poorly controlled symptomatic brady- or tachy-arrhythmias 11. Uncontrolled hypertension (BP \> 180 mmHg systolic and/or \>105 mmHg diastolic) or hypotension (BP \< 90 mmHg systolic) at baseline 12. Presence of severe mitral annular calcification 13. Prior mitral valve surgery 14. Presence of a mechanical mitral heart valve, mitral bio-prosthetic valve or mitral annuloplasty ring 15. Echocardiographic evidence of intracardiac mass, thrombus, or vegetation 16. Active endocarditis 17. Severe aortic stenosis (aortic valve area \<1.0 cm2) or severe aortic regurgitation 18. Infiltrative cardiomyopathies (e.g., amyloidosis, hemochromatosis, sarcoidosis) 19. Hypertrophic cardiomyopathy, restrictive cardiomyopathy, constrictive pericarditis, or any other structural heart disease causing heart failure other than atrial functional mitral regurgitation 20. Subjects with echocardiographic documentation of non-compaction cardiomyopathy with associated hypercontractility of the cardiac structures supporting the mitral annulus 21. Hemodynamic instability requiring inotropic support or mechanical heart circulatory support 22. Active infections requiring current antibiotic therapy 23. Severe right ventricular failure or severe tricuspid regurgitation 24. History of bleeding diathesis or coagulopathy, or subject who refuses blood transfusions 25. Significant organic mitral valve pathology (e.g., moderate or severe myxomatous degeneration, with or without mitral leaflet prolapse, rheumatic disease, full or partial chordal rupture) 26. Allergy to contrast dye that cannot be pre-medicated 27. Pregnant or planning pregnancy within next 12 months. 28. Chronic severe pathology limiting survival to less than 12-months in the judgement of the investigator 29. Anticipated need of left ventricular assist device within twelve (12) months 30. Currently participating or has participated in another investigational study where the study primary endpoint was not reached at the time of screening 31. Patient requires emergent/emergency treatment for mitral regurgitation