FDA Approved Non-Warfarin and Reduced Warfarin Anticoagulation Trial of the On-X Prosthetic Heart Valve Initiated at Emory Crawford Long Hospital.

AUSTIN, Texas -- Successful Completion Could Result in First-Ever Low-Dose Anticoagulation Therapy Recommendations for a Mechanical Heart Valve

Medical Carbon Research Institute L.L.C. (MCRI(TM)) today announced initiation of the FDA approved clinical trial PROACT (Prospective Randomized On-X(R) Prosthetic Heart Valve Anticoagulation Clinical Trial) being conducted under an investigational device exemption (IDE) at reduced anticoagulation levels at Emory Crawford Long Hospital, Emory University in Atlanta, Georgia. The study began with the approval of the Crawford Long and Emory University Institutional Review Board and the first implantation of the On-X valve under the approved protocol and is also being conducted at 19 other prestigious institutions throughout the US. Successful completion of the clinical study could result in the On-X valve becoming the only mechanical heart valve approved for low-dose anticoagulation therapy.

Based on existing clinical data and the submitted protocol, the FDA has determined that a clinical trial of the On-X valve with three specific patient groups at reduced anticoagulation levels is clinically reasonable. The patient groups include a non-warfarin group of low-risk aortic valve replacement patients and two low-dose warfarin groups of higher risk aortic valve replacement patients and mitral valve replacement patients. Higher risk patients include those with heart rhythm problems, left ventricular dysfunction, carotid and peripheral arterial disease and condition of hypercoagulability.

The investigation is led by John D. Puskas, M.D., Chief of Cardiac Surgery at Emory Crawford Long Hospital and Associate Chief, Division of Cardiothoracic Surgery at Emory University School of Medicine in Atlanta, and is expected to be complete after five years of follow-up.

"We are extremely pleased to have initiated this important study. This is the first FDA trial to explore lower anticoagulation with mechanical heart valves," said Dr. Puskas. "The On-X valve has design and material features that make us hopeful that it may function well at lower levels of blood-thinning medications. If this trial proves that On-X valve recipients are able to take a lower level of anticoagulant, it will help to reduce the potential incidence of bleeding complications caused by taking the higher dosages of Coumadin normally prescribed after receiving a mechanical heart valve."

Omar M. Lattouf, M.D., one of the senior participating surgeons at Emory Crawford Long Hospital and Director of the Emory Center for Device Innovation, implanted the On-X Prosthetic Heart Valve into the first patient admitted into the study on June 6, 2006. According to Dr. Lattouf, "Although nearly all heart valve patients can be included in this study, the protocol requires very specific testing to determine the appropriate study group for each patient. This patient is well suited for the study and will be placed in the appropriate study group following the three-month post-operative period."

According to study protocol, the low-risk aortic patient group will be maintained using non-warfarin anticoagulation medication of clopidogrel and aspirin. Higher-risk aortic patients will be maintained using warfarin (Coumadin(R)) at reduced International Normalized Ratio (INR) levels of between 1.5 and 2.0, plus aspirin. The mitral valve replacement patients will be maintained with warfarin at a target INR of 2.0 to 2.5 and aspirin. The first three months for all patient groups include traditional warfarin anticoagulation protocols. To ensure that patients remain within target INR range, each patient will be required to self-monitor their anticoagulation levels. Results of this self-monitoring will be communicated to the patient's physician.

Clyde Baker, President MCRI notes that, "The FDA approved Reduced Anticoagulation Clinical Trial provides reinforcement for patient involvement in the valve selection decision as recommended by the new guidelines, which state that 'The decision (of which prosthesis to implant) requires full discussion with the patient, with the understanding that there is a higher chance of the need for reoperation with a bioprosthesis.' Present life expectancy of a 65-year-old in the US is approximately 20 years and increasing rapidly. With tissue valves typically experiencing structural valve deterioration at 10 to 15 years, it is a very serious decision to implant a valve knowing that a reoperation is likely." Baker concludes, "The trial is being conducted in 20 highly respected institutions in the US and may provide patients with a quality of life and life expectancy formerly only available to individuals without valvular heart disease. We have seen a dramatic increase in the number of patients under the age of 65 years old who study their available valve options and make a decision to have the On-X valve implanted, primarily due to the potential of improved quality of life and the desire to avoid a reoperation at an advanced age."

Go to http://www.onxvalves.com/about_news_item.asp?NewsID=30 for complete news release.