Three cases of neutralization of factor Xa inhibitors with andexanet alfa under rotational thromboelastography monitoring

BackgroundFactor Xa inhibitors are direct oral anticoagulants that are extremely useful in clinical applications, safe, and do not require dose adjustment. It is desirable to be able to monitor their effects in the event of hemorrhagic complications requiring neutralization. However, it is difficult to monitor their activity and neutralization using conventional coagulation tests.Case PresentationWe report three patients taking factor Xa inhibitors who underwent rotational thromboelastography (ROTEM) monitoring before and after neutralization with andexanet alfa. All three patients had hemorrhagic complications that required neutralization of their factor Xa inhibitors using andexanet alfa. One ROTEM parameter, the EXTEM clotting time (EXTEM-CT), was immediately shortened after andexanet alfa bolus administration, without subsequent extension of the EXTEM-CT assessed 4 h after the bolus dose.ConclusionROTEM parameters, particularly EXTEM-CT, might be useful for monitoring neutralization of factor Xa inhibitors. Rotational thromboelastography, a viscoelastic device, can objectively evaluate the effect of Xa inhibitors, which is difficult to evaluate by usual coagulation tests, and showed rapid response before and after andexanet alfa administration.image