Safety and Efficacy of the HighLife Transcatherter Mitral Valve Replacement System in Patients With Moderate-severe or Severe Mitral Regurgitation in China

Inclusion Criteria: 1. Patients who voluntarily participate and sign the informed consent form and can cooperate with the completion of the entire trial process; 2. Age ≥ 18 years old; 3. Moderate-severe or severe mitral regurgitation (≥3+); Note 1: Patients with ischemic or non-ischemic heart disease induced symptomatic secondary mitral regurgitation as the primary cause must be treated for at least 1 month after optimal guideline medical therapy (GDMT). Echocardiography should be performed 3 months after cardiac resynchronization therapy and 1 month after coronary revascularization to assess the degree of regurgitation. Note 2: For patients with primary mitral regurgitation, the multidisciplinary cardiac team of the research center needs to use a standard scoring system, considering multiple factors such as complications, frailty, and disability, ensuring the enrolled with a high risk of surgery. 4. Patients with New York Heart Association (NYHA) functional ratings are Class II, III, or ambulatory Class IV; 5. Anatomically appropriate for treatment with the HighLife Transcatheter Mitral Valve Replacement System. Exclusion Criteria: 1. Patients had any stroke/TIA within 30 days; 2. Patients with severe symptomatic bilateral carotid stenosis (\>70% stenosis on non-invasive imaging); 3. Patients with active infection requiring antibiotic therapy; 4. Patients with active ulcer or gastrointestinal bleeding within the past 3 months; 5. Patients with history of coagulopathy or refuse future blood transfusion; 6. Patients unable to undergo transesophageal echocardiography (TEE); 7. Patients who are pregnant or breastfeeding, or planning to have children within 12 months; 8. Patients who are unable to adhere to the follow-up schedule and complete the examination; 9. Patients enrolled in other clinical studies and within the follow-up period; 10. Patients with known allergies to device components or contrast agents; 11. Patients unable to receive anticoagulant or antiplatelet therapy; 12. Patients with a life expectancy of less than 12 months due to non-cardiac disease; 13. Patients requiring emergency surgical treatment; 14. Patients scheduled for cardiac surgery within 12 months; 15. Patients with an inappropriate mitral annulus or leaflet size (\<30 mm and \>45 mm); 16. Patients with moderate or above mitral stenosis; 17. Flail mitral leaflets, or moderate to severe mitral valve prolapse; 18. Patients with severe hepatic or renal insufficiency; 19. Patients with severe calcification of the mitral annulus and/or mitral leaflets; 20. Patients with history of mitral valve surgery or interventional therapy, or left atrial appendage occlusion device; 21. Patients had acute myocardial infarction (MI) (Q-wave MI, or non-Q-wave MI, with CK-MB twice the normal and/or T-MB) within the past 1 month; 22. Patients with untreated symptomatic coronary lesions requiring revascularization; 23. Patients with untreated severe aortic stenosis and severe aortic regurgitation; 24. Patients with aortic valve prosthesis; 25. Patients with severe tricuspid valve lesions requiring surgical intervention; 26. Patients with significant right ventricular dysfunction (such as biliteral lower extremities edema with increased jugular vein pulsation and hepatomegaly; 27. LVEF \< 30%; LVEDD \> 70 mm; 28. Patients with echocardiographically confirmed intracardiac mass, thrombus or neoplasm; 29. Hypertrophic obstructive cardiomyopathy (HOCM); 30. Patients with active or recent (within 3 months) endocarditis; 31. Patients with definite non-left heart disease induced severe pulmonary hypertension (echocardiographic indication: systolic pulmonary artery pressure (SPAP) \> 70 mmHg) 32. Patients with hypotension (systolic blood pressure \<90 mmHg) occurring within 7 days or mechanical hemodynamic support.