Apixaban or Warfarin in Patients with an On-X Mechanical Aortic Valve

BackgroundVitamin K antagonists are the only oral anticoagulants approved to prevent valve thrombosis and valve-related thromboembolism in patients with mechanical heart valves. Whether an On-X aortic can be safely anticoagulated apixaban is unknown.MethodsPatients implanted at least 3 months before enrollment were randomly assigned receive 5 mg twice daily or warfarin (target international normalized ratio 2.0 3.0). The primary efficacy end point was composite of coprimary analyses comparing for noninferiority event rate objective performance criterion (OPC).ResultsThe trial stopped after 863 participants enrolled owing excess thromboembolic events group. Most (94%) took aspirin. A total 26 end-point occurred, 20 (in 16 participants) group (4.2%/patient-year; 95% confidence interval [CI], 2.3 6.0) 6 (1.3%/patient-year; CI, 0.3 2.3). difference rates between groups 2.9 (95% 0.8 5.0); OPC success criteria not met. Major bleeding 3.6%/patient-year 4.5%/patient-year warfarin.ConclusionsApixaban did demonstrate less effective than prevention valve. (Funded by Artivion; ClinicalTrials.gov number, NCT04142658.)