To confirm the effectiveness and safety of the DragonFly M2 Transcatheter Mitral Valve Repair System for the treatment of symptomatic moderate-to-severe (3+) or severe (4+) degenerative mitral regurgitation in high surgical risk subjects.The safety and effectiveness of the first-generation device(Dragonfly Transcatheter Mitral Valve Repair System)have been previously demonstrated. This study aims to further confirm the safety and effectiveness of the new device following structural optimization based on the first-generation design.

This is a prospective, multicentric clinical investigation.

Subjects to be included in this clinical investigation suffer from symptomatic chronic moderate-to-severe (3+) or severe (4+) DMR with high or prohibitive surgical risk judged by a local investigation site's heart team .

After signing an informed consent form, subjects in the experimental group will undergo the transcatheter mitral valve repair procedure using the DragonFly M2 Transcatheter Mitral Valve Clip System. All subjects were followed up immediately after procedure, before discharge, 30 days , 6 months, 12 months after procedure, and 2, 3, 4, and 5 years after procedure.

Inclusion Criteria:

1.≥ 18 years old. 2.Moderate to severe (3+) or severe (4+) chronic DMR determined by transthoracic echocardiography.

• Transseptal catheterization is determined to be feasible by the Investigator.
• Patients 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:

1)Echocardiographic evidence of intracardiac mass, thrombus, or vegetation. 2) The presence of other severe heart valve disease requiring surgical intervention.

3) Prior mitral valve leaflet surgery or transcatheter mitral valve intervention.

• Currently participating in an investigational drug or another device study that has not completed its primary endpoints or would clinically interfere with the endpoint of this study. Note: Trials requiring extended follow-up for products that were investigational, but have since become commercially available, are not considered investigational trials.
• In the judgment of the investigator, subjects may not complete the trial according to poor compliance or in other circumstances when the investigator determines that the subject is unfit to participate in the study.