Correlation between heparin anti‐Xa activity and thromboelastography in adult critically ill COVID‐19 patients

Study Objective Severe coronavirus disease 2019 (COVID‐19) increases the risk of thrombotic complications with unfractionated heparin (UFH) as a commonly used agent in managing venous thromboembolism (VTE). The optimal anticoagulation intensity and monitoring parameters in intensive care unit (ICU) COVID‐19 patients remains controversial. The primary study aim was to evaluate the relationship between anti‐Xa and thromboelastography (TEG) reaction (R) time in patients with severe COVID‐19 receiving therapeutic UFH infusions. Design Single‐center, retrospective study conducted over a 15‐month period (2020–2021). Setting Academic medical center (Banner University Medical Center Phoenix). Patients Adult patients with severe COVID‐19 administered therapeutic UFH infusions with one or more corresponding TEG, and anti‐Xa assessments drawn within ≤2 hours of each other were included. The primary end point was the correlation between anti‐Xa and TEG R time. Secondary aims were to describe the correlation between activated partial thromboplastin time (aPTT) and TEG R time, as well as clinical outcomes. Pearson's coefficient was used to evaluate the correlation using a kappa measure of agreement.