Commentary: Association of Anemia with Venous Thromboembolism in Acutely Ill Hospitalized Patients: An APEX Trial Substudy

Anemia, commonly defined as hemoglobin concentration <12.0 g/ dL in women and <13.0 g/dL in men, is a prevalent condition that has been linked to unfavorable prognosis among hospitalized patients. Populationbased studies report that low hemoglobin level is associated with various thrombotic disorders including myocardial infarction, stroke, and venous thromboembolism (VTE). A recent study on acutely ill hospitalized patients extends the previous findings and demonstrates that anemic patients were at a greater risk for symptomatic VTE through 77 days of follow-up. Specifically, decreased hemoglobin concentration was associated with a two-fold risk of symptomatic DVT or non-fatal PE, despite the provision of pharmacologic thromboprophylaxis with enoxaparin or betrixaban, an FDA approved direct oral anticoagulant for VTE prevention. Additionally, hemoglobin measurement improved the risk discrimination and reclassification of a well-validated VTE assessment tool (i.e., International Medical Prevention Registry on Venous Thromboembolism [IMPROVE] VTE risk score). Based on these results, future studies should evaluate the use of laboratory biomarkers in conjunction with clinical variables to refine individualized VTE risk assessment.