90 Evaluation of a Protocol For Heparin Initiation in Patients Transitioning from Oral Factor Xa Inhibitors

Introduction: Transitioning from oral factor Xa inhibitors (FXaI) to unfractionated heparin infusion (UFH) can be challenging when using anti-Xa levels for heparin monitoring. The presence of residual factor Xa inhibition can result in elevated heparin anti-Xa levels and subsequent heparin infusion interruptions and/or adjustments. Activated partial thromboplastin time (aPTT), which is minimally affected by residual FXaI, is an alternative heparin monitoring strategy, but disregards residual FXaI anticoagulant effects.We created a transition protocol which is individualized to the patient based on the indication for heparin and baseline anti-Xa level.