Interim data from PROACT study confirm patients with On-X Plus 1.5 valve may be safely maintained at anticoagulation levels below current recommended guidelines


Interim results from the PROACT (Prospective randomised On-X anticoagulation clinical trial) study indicate that patients with the On-X Plus 1.5 aortic heart valve may be safely managed at lower INR rates with statistically significant reductions in bleeding events and no increase in thromboembolic events even in higher risk patients.

PROACT principal Investigator John D Puskas (professor of Cardiothoracic Surgery, Icahn School of Medicine at Mount Sinai, and Chairman, Department of CT Surgery, Mount Sinai Beth Israel, New York, USA) presented updated data that provide, according to a company press release, compelling support for the adoption of a lower level of anticoagulation with the On-X Plus 1.5 device during the “New nuggets from late-breaking clinical trials” session at the annual meeting of the European Association of Cardio-Thoracic Surgeons (EACTS; 11–15 October, Milan, Italy).

The interim PROACT trial results have provided the basis for the recent submission of a revised, reduced anticoagulation guideline for the On-X valve instructions for use (IFU). The revised IFU may permit patients with On-X aortic valves to be managed at an INR level of 1.5 to 2.0, which is closer to an unmedicated INR. CE approval was obtained for this reduced anticoagulation in January 2014, and FDA approval is pending.

The PROACT trial for the On-X aortic valve studied an INR range of 1.5-2.0 INR for aortic valve patients who were at higher than normal risk of thromboembolism. According to Puskas, the lower target INR in the PROACT trial resulted in a statistically significant reduction of 65% in bleeding events for the test patients without an increase in thromboembolic events. He says: “The major concern with the use of anticoagulants such as warfarin has been bleeding risk. 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.”