CardioFlow Transcatheter Mitral Valve Replacement System Pre-market Clinical Investigation

Subjects must meet all of the following criteria to be included in the study: * Subject has symptomatic, moderate-to-severe or severe, degenerative mitral regurgitation(MR≥3+); * NYHA functional class≥ II; * Heart team agrees that patient is unsuitable for treatment with conventional mitral valve surgery or transcatheter mitral valve edge-to-edge repair； * Subjects age ≥65 years old; * Subjects willing to sign Informed Consent for participation in the study and return for all required post-procedure follow-up visits; * Subjects anatomically suitable for the transcatheter mitral valve implantation Subjects will be excluded from the study if any of the following conditions are present： * Left ventricular ejection fraction (LVEF)\<30%； * Left ventricular end diastolic diameter (LVEDD)\>7.5cm； * Cardiac echography evidence of intracardiac mass, thrombus, or vegetation； * Severe tricuspid regurgitation with severe right ventricular dysfunction or any tricuspid valve disease requiring surgery or transcatheter intervention； * Aortic valve diseases requiring surgery or transcatheter intervention； * Any prohibitive mitral annular calcification(annulus to the leaflet) interferes the expansion of the device； * Prior surgical treatment of mitral valve； * Therapeutic cardiac surgical or interventional procedure within 30 days prior to the index procedure； * End-stage heart failure requiring left ventricular assist device or cardiac transplantation * Subjects with severe major vascular disease requiring surgical intervention or with aortic dissection * Need for emergent surgery * Hypertrophic or restrictive cardiomyopathy, constrictive pericarditis * Mitral valve pathological anatomy，LVOT anatomy, left atrial or ventricle anatomy not applicable for the investigational device implantation； * Concurrent medical condition with a life expectancy of less than 12 months * Evidence of an acute myocardial infarction or untreated clinically significant coronary artery disease requiring revascularization within 30 days of enrollment. * Recent cerebrovascular events(ischemic or hemorrhage stroke, not including TIA) within 3 months of enrollment * Severe carotid stenosis( \> 70%, both sides of carotid artery) * Any of the following: leukopenia, acute anemia, thrombocytopenia, history of bleeding diathesis, or coagulopathy if cannot be adequately treated； * Active endocarditis or active other infection * Active peptic ulcer or history of upper gastrointestinal bleeding within 3 months * Subject refuses the blood transfusion; * Known hypersensitivity or contraindication to nitinol (titanium or nickel),bovine product, PET(Polyethylene terephthalate), contrast media; Inability to tolerate anti-platelet or anticoagulants therapy; Contraindicated for transesophageal echocardiography (TEE) * Condition that prevents transapical access, such as chest malformation, ventricular aneurysm, apical thinning * Subjects with rheumatic mitral stenosis * Acute exacerbation of chronic obstructive pulmonary disease * Per heart team assessment, conditions that not suitable for transcatheter mitral valve replacement * Severe disabling Alzheimer's disease * Currently participating in an investigational drug or another device study that has not yet reached its primary endpoint