DragonFly EU Pivotal Study

Inclusion Criteria: * ≥18 years old * New York Heart Association (NYHA) Class II-IV * Moderate to severe (3+) or severe (4+) chronic DMR determined by transthoracic echocardiography (For DMR cohort) * Symptomatic FMR ≥ 3+ due to ischemic or non-ischemic cardiomyopathy (For FMR cohort) * Transseptal catheterization and femoral vein access are determined to be feasible * Subjects have been informed of the nature of the study, understand the purpose of the clinical trial, voluntarily participate in the study, and sign the ICF Exclusion Criteria: * Echocardiographic evidence of intracardiac mass, thrombus or vegetation * Other severe heart valve diseases requiring intervention * Prior mitral valve leaflet surgery (prior annuloplasty ring not excluded) or previous transcatheter mitral valve intervention * Acute myocardial infarction occurred within 4 weeks, or untreated severe coronary artery stenosis requiring revascularization * Any cardiovascular intervention within 30 days or cardiac surgery within 6 months prior to the procedure; or in the judgment of the investigator, the femoral vein cannot accommodate a 25 F catheter or the presence of an inferior vena cava filter would interfere with advancement of the catheter or ipsilateral deep vein thrombosis is present; or the patient's anatomy is not suitable for atrial septal puncture * Patients in whom TEE or general anesthesia is contraindicated * End stage heart failure (ACC/AHA stage D); or after heart transplantation; or waiting for a heart transplantation * Active endocarditis or active rheumatic heart disease; or mitral valve changes due to endocarditis and rheumatic heart valve disease * History of ischemia cerebrovascular accident in the past 30 days, or severe symptomatic carotid stenosis (ultrasonic examination showed stenosis degree \>70%); or carotid stent implantation within 30 days; hemorrhagic cerebrovascular accident occurred within 6 months * History of acute peptic ulcer or gastrointestinal bleeding within 3 months * Hemorrhagic disease or coagulation disorder; or contraindicated of antithrombotic drug treatment * Modified Rankin scale ≥ 4 * Diseases that make the evaluation of treatment difficult (e.g., cancer, severe metabolic disease, psychosis) * Pregnant or lactating women * Hemodynamic instability defined as systolic pressure \< 90 mmHg without afterload reduction medicine, or cardiogenic shock, or need for an intra-aortic balloon pump, or other hemodynamic support devices * Active infections requiring current antibiotic therapy (if temporary illness, patients may be enrolled 2 weeks after discontinuation of antibiotics) * Currently participating in an investigational drug or another device study of which the primary endpoint has not been completed, or it that clinically interferes with the current study endpoints. (Note: extended follow-up for products that were investigational, but have since become commercially available, are not considered investigational study) * In the judgment of the investigator, the patients' compliance will be poor and could not complete the study as required, or other conditions indicate that the subject is not suitable to participate in the study