On-X Life Technologies, Inc. (On-X LTI) announced today that it is highlighting the recent interim results the PROACT (Prospective Randomized On-X Anticoagulation Clinical Trial) at the European Association of Cardio-Thoracic Surgeons Meeting being held October 5-9, 2013, in Vienna, Austria.

The interim results of the PROACT trial provide evidence that patients may be safely managed with less aggressive anticoagulant therapy than is currently recommended by the American Heart Association and American College of Cardiology after replacement of the aortic valve with an On-X mechanical prosthesis. In this series of 375 aortic valve replacement patients, those managed with lower anticoagulation had reduced bleeding complications compared to those patients treated with standard doses of anticoagulation as are used for other mechanical heart valves.

The interim results were previously presented at the American Association for Thoracic Surgery Annual Meeting (AATS) by John D. Puskas, M.D., M.Sc. Chief of Cardiac Surgery—Emory University Hospital Midtown, Associate Chief of Cardiothoracic Surgery—Emory University and International Principle Investigator for the PROACT trial.

“The major concern with use of anticoagulants such as warfarin is bleeding,” said Dr. Puskas. “The interim PROACT trial results show that On-X aortic heart valve recipients can be safely maintained at much lower INR levels than have been used for other mechanical heart valves thereby significantly reducing the risk of bleeding complications.” The level of anticoagulation activity is measured as international normalized ratio (INR). INR is used to determine the clotting tendency of blood. INR in the absence of anticoagulation therapy is normally 0.8-1.2. The target range for INR in anticoagulant use (e.g. warfarin) varies, depending upon indication for therapy. Professional societies have recommended that patients with mechanical aortic heart valves in the absence of thromboembolic risk factors be maintained at 2.0-3.0 INR.

The trial for the On-X aortic valve studied an INR range of 1.5-2.0 INR for aortic valve patients at higher than normal risk of thromboembolism . The lower target INR in the PROACT trial has resulted in a statistically significant reduction of over 50% in bleeding events for the test patients.

The interim PROACT trial results provide the basis for the recent submission for regulatory reviews of a revised, reduced anticoagulation guideline for the On-X valve Instructions for Use (IFU). The revised IFU may permit patients to be maintained at INR levels below those generally accepted by professional societies for mechanical valves.

“The interim PROACT trial results show reduced bleeding events for patients who receive the On-X aortic valve, a data point that is extremely meaningful for patients who are in the process of choosing a prosthetic valve,” said Clyde Baker, On-X Life Technologies CEO. “Pending review and approval by FDA, younger aortic heart valve replacement patients — those 65 years and under — may have a much safer and permanent solution to aortic valve disease. They can make a choice for low complications and likely not be faced with the trauma of a future cardiac reoperation.”