Learn More About MR

Viacor is a development stage company dedicated to pioneering catheter-based techniques for the treatment of heart valve disease contributing to congestive heart failure (CHF). Since late 2000, Viacor has focused on the percutaneous treatment of mitral regurgitation (MR) in CHF patients via a novel coronary sinus-based annuloplasty approach.

The Mitral Valve and MR

The mitral valve controls blood flow between the left atrium and the left ventricle of the heart. The valve has two leaflets (flaps) that open to let blood into the ventricle and then close when the ventricle squeezes blood out to the body.

MR is a condition whereby the blood leaks or back flows between the atrium and ventricle. Leakage often is caused by mitral valve prolapse, where the flaps don’t close properly. This condition can cause blood to backup into the left atrium and the lungs, enlarge and damage the left ventricle, reduce cardiac output, and ultimately lead to heart failure. It is well documented that MR significantly worsens outcomes for CHF patients. Mortality at twelve months is typically 28% for patients with MR versus 12% for those free of MR.

An estimated 5 million patients in the United States and 20 million worldwide suffer from CHF. Incidence of CHF is increasing in the total patient population at a rate of 3-5% annually; over 500,000 new patients are diagnosed each year. Over 750,000 patients in the United States alone have associated functional MR.

Existing Treatment Options for MR

Currently there are two surgical treatment options for functional mitral regurgitation: mitral annuloplasty and mitral valve replacement. When successful, these surgical alternatives deliver excellent chronic efficacy and improved long term outcomes. Unfortunately, these cardiac surgical procedures have associated morbidity and mortality, and consequently only a small percentage of CHF patients suffering from MR are referred for surgery. The current dominant treatment option for patients with CHF and associated MR is medical management, which fails to address the MR directly.

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VIACOR's Technology

To address MR directly, Viacor has developed a percutaneous mitral annuloplasty (PTMA™) system that takes advantage of the close anatomical relationship between the mitral valve and the coronary venous system. The PTMA™ device resides within the coronary sinus vein as a permanent implant (see Video Clip above right on this page).

The proposed Viacor method has unique advantages over both current surgical methods, and the other proposed percutaneous methods for mitral annuloplasty:

• We believe the Viacor method most closely approximates the anatomical correction delivered by conventional surgical annuloplasty. The Viacor system is designed to deliver the desired correction to the posterior mitral annulus while curving to a radius that closely mimics an annuloplasty ring.
• The PTMA™ effect is assessed in a reversible diagnostic method before permanent implantation, allowing physicians to screen patients with a minimal-risk, catheterization lab procedure.
• The Viacor method facilitates late adjustment of treatment effect.

Please view our Bibliography page for further information about MR and the Viacor PTMA™ device.

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Status

Viacor has an investigational device exemption with the FDA, and plans to file for approval to undertake an implant pilot study in the United States. We expect initial commercial release of the Viacor PTMA™ system to be outside the United States, and then within the United States contingent on FDA approval.

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Animation of a mitral valve.
File size: 1.8 MB.