Rivaroxaban-calibrated chromogenic anti-Xa assay in cirrhosis: Use to rule out disseminated intravascular coagulation

Peritoneovenous shunts (PVSs) are used to relieve ascites in cirrhosis. Disseminated intervascular coagulation (DIC) is a complication of PVSs requiring immediate PVS removal. We report a patient who developed new elevations of prothrombin time (PT) and activated partial thromboplastin time (aPTT) 6 hours after PVS placement, concerning for new-onset DIC. We address the key clinical question of distinguishing DIC from rivaroxaban effect on labs. The patient took rivaroxaban 3 hours after PVS placement, suggesting rivaroxaban effect. Rivaroxaban-calibrated anti-Xa level was in the expected treatment range. Over 12 hours, coagulation labs and rivaroxaban levels declined, with no evidence of DIC. The sudden PT/aPTT increase was attributed to rivaroxaban, however, the distinction between DIC and rivaroxaban effect was possible only with the rapid availability of rivaroxaban levels. While there are no US Food and Drug Administration-approved tests for rivaroxaban levels in the United States, this case demonstrates they can have significant clinical impact, encouraging more widespread adaptation of these assays.