Low-Dose Warfarin With a Novel Mechanical Aortic Valve: Interim Registry Results at 5-Year Follow-Up

This study evaluated the safety of low-dose warfarin (target INR 1.8) combined with daily aspirin (75 100 mg) after On-X mechanical aortic valve implantation. The results showed that the composite rate of major bleeding, valve thrombosis, and thromboembolism was significantly lower in the low-dose warfarin group (1.83 percent) compared to the standard-dose warfarin group (5.39 percent), with reductions in major bleeding and total bleeding by 87 percent and 71 percent, respectively. There was no increase in thromboembolic events, and the outcomes were consistent regardless of home or clinic monitoring. These interim findings support the continued safe use of low-dose warfarin and aspirin as a safe anticoagulation strategy for patients with an On-X valve at five years.