The purpose of this study is to assess the safety and performance of Transcatheter Mitral Valve Replacement (TMVR) system for the treatment of severe, symptomatic mitral regurgitation (MR).

The treatment guidelines for valvular heart disease indicate that surgical correction of primary mitral valve regurgitation (MR) is a Class I recommendation. Recent evidence indicates that valve replacement is at least as effective as repair in both primary and secondary MR patients. However, many patients are not referred for surgery as they are considered to be too high of a risk to undergo on-pump, open-heart procedures. Percutaneous aortic valve replacement has made treatment of stenosed aortic valves available to high-risk surgical patients who would have otherwise been medically managed. Percutaneous mitral valve (MV) replacement offers similar advantages. The feasibility of percutaneous MV replacement has been demonstrated in early feasibility studies. To meet this medical need, Caisson Interventional has developed a percutaneous delivery system for a bioprosthetic mitral valve. As with patients with aortic valve (AV) deficiencies, this device can be used to provide needed therapy to patients who might not otherwise receive treatment beyond medical therapy. This study will provide information on the safety and performance of this system.

Inclusion Criteria:

• Has severe mitral regurgitation
• New York Heart Association (NYHA) Class II, III, IVa or heart failure
• High risk for cardiovascular surgery

Exclusion Criteria:

• Excessive calcification or thickening of mitral valve annulus
• Severe mitral stenosis, fused commissures, valvular vegetation or mass
• Left ventricular end diastolic dimension > 7cm
• Left ventricular outflow tract obstruction
• Severe right ventricular dysfunction
• Stroke within 90 days; transient ischemic attack or myocardial infarction within 30 days of the index procedure