Inclusion Criteria:  Patients with severe secondary MR characterized, according to the European guidelines and recommendations, by a regurgitant volume ≥30 mL/beat or an effective regurgitant orifice ≥20 mm². Symptomatic patients with New York Heart Association Class ≥II. Left ventricular ejection fraction between 15% and 50%. Optimal standard of care therapy for heart failure according to investigator. Not eligible for a mitral surgery intervention according to the Heart Team. Patients who have the ability to understand the requirements of the study and provide written consent/assent to participate and agree to abide by the study requirements.  Exclusion Criteria:  Participants younger than 18 years Pregnancy or breastfeeding Severe impaired renal function (GFR < 15 ml/min) Patients with untreated severe concomitant valve disease (e.g. severe tricuspid valve regurgitation, aortic stenosis) The patient has a medical condition, serious concurrent illness, or extenuating circumstance that would significantly decrease study compliance, including all prescribed follow-up The patient has contraindications to CMR, including: Implanted non-CMR conditional metallic implants, pacemaker, intracardiac defibrillator, neurostimulator, epicardial pacemaker leads, or any abandoned leads, ferromagnetic aneurysm clip, ferromagnetic halo device, cochlear implants, implanted infusion pumps or severe claustrophobia The patient is clinically unstable or has stage D congestive heart failure or inability to lay flat for 60 minutes