DragonFly M2 Pivotal Study

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.