Background: Anticoagulation therapy in hospitalized patients is inherently high-risk with complex dosing requirements and significant potential for drug interactions. Heparin is an anticoagulant that utilizes laboratory monitoring to target therapeutic concentrations, but accuracy of anti-Xa levels can be falsely elevated due to recent direct oral anticoagulant (DOAC) exposure. Our practice advisories (OPAs) are utilized within the electronic health record (EHR) to improve clinical decision-making and advance patient safety. The study site employs OPA alerts to identify elevated anti-Xa levels in patients who may have had recent exposure to a DOAC with the goal of helping practitioners decide if a reagent that removes DOAC effect on anti-Xa (DOAC-StopTM) should be utilized. The objective of this study was to analyze the impact of an OPA for elevated anti-Xa levels in patients receiving heparin infusions with recent potential or known DOAC exposure, focusing on clinical appropriateness of DOAC-StopTM utilization and safety outcomes. Methods: This single center, retrospective cohort study analyzed patients with an elevated anti-Xa OPA alert(s) between January 1st and April 3rd, 2024 focusing on clinical appropriateness and safety outcomes. OPAs alerted for patients who were on a heparin infusion, had an elevated anti-Xa ≥ 1, and were within three days of admission or had documented receipt of a DOAC within the previous five days. Exclusion criteria included pregnancy, incarceration, switching between heparin protocols during the admission, and administration of enoxaparin within 24 hours of the elevated anti-Xa. The primary outcome assessed the appropriateness of subsequent actions in response to the OPA. Appropriateness was defined based on a treatment flowchart developed for study. Secondary outcomes included incidence of bleeding within 24 and 48 hours of the alert(s) per the International Society on Thrombosis and Haemostasias (ISTH) bleeding criteria and a subgroup analysis of DOAC-StopTM utilization by level of care and nursing shift. Results: A total of 100 patients were included in the final analysis. At baseline, 46% of patients were receiving apixaban, 6% rivaroxaban, and 48% were not receiving any anticoagulant within the 72 hours prior to heparin initiation. Clinical use of DOAC-StopTM following the first OPA was deemed appropriate for 92% of initial advisories and inappropriate for 8%. Inappropriate use, according to the study-developed flowchart, included administering DOAC-Stop™ to patients without prior DOAC exposure and omitting it in high-risk patients with prior exposure. There was no statistically significant difference between appropriate clinical use based on time of shift (p = 0.426) or by level of care (p = 0.119). Bleeding events were mostly attributable to clinically relevant non-major bleeding or major bleeding defined as a hemoglobin decrease of 2 mg/dL or more that required no clinical intervention. These events occurred within 0-24 hours in 11% of patients and within 0-48 hours in 18% of patients. Conclusions: While the true effect of this OPA is difficult to discern given lack of a control group, the high level of appropriate advisory response indicates that it was successful in identifying potential candidates for DOAC-StopTM and ensuring that high-risk patients received adequate anticoagulation evaluation. Practice advisories and protocols do not account for every scenario, and clinical judgement must be utilized to determine candidacy for DOAC-StopTM.
