Beating Heart Mitral Valve Repair With the HARPOON™ System

The objective of the study is to evaluate the safety and effectiveness of the HARPOON™ System in the treatment of patients with severe degenerative mitral regurgitation (DMR).

Inclusion Criteria: Each subject is required to meet all of the following inclusion criteria: 1. Patient is \>/= 21 years old. 2. Presence of severe degenerative mitral regurgitation with mid-segment posterior leaflet prolapse (without commissural involvement) by echocardiographic study. 3. Mitral leaflet coaptation surface sufficient to reduce mitral regurgitation without undue leaflet tension, based on the judgment of the Echocardiographic Core Lab. 4. Patient competent to sign informed consent and able to return for follow-up and is capable of participating in all testing associated with this clinical investigation. Exclusion Criteria: Patients will be excluded if ANY of the following criteria apply: 1. Functional mitral regurgitation (FMR). 2. Evidence of anterior or bileaflet prolapse. 3. Severe mitral annular calcification (MAC). 4. Moderate or greater leaflet calcification. 5. Fragile or thinning apex (e.g. LV aneurysm). 6. Have undergone cardiac or peripheral vascular procedures within 30 days prior to the trial procedure. 7. Planned cardiac or peripheral vascular procedures within 30 days after the trial procedure. 8. Requirement for concomitant cardiac surgery. 9. Severe pulmonary hypertension (pulmonary artery systolic pressure \> 60mmHg). 10. Severe aortic stenosis or insufficiency. 11. Severe tricuspid regurgitation. (Patients with mild or moderate tricuspid regurgitation are not excluded.) 12. Left ventricular ejection fraction (LVEF) \