To observe and evaluate the safety and efficacy of the HighLife Transcatheter Mitral Valve Replacement System in patients with moderate-severe or severe mitral valve regurgitation through a prospective, multicenter clinical trial using objective performance criteria.

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.