Prevalence and consequences of empiric anticoagulation for venous thromboembolism in patients hospitalized for COVID-19: a cautionary tale

Abstract

Patients hospitalized with novel coronavirus disease 2019 (COVID-19) have increased risk of venous thromboembolism (VTE) [1, 2].Traditionally, diagnosis of VTE is radiographically confirmed with ultrasound or computed tomography. Due to the large number of patients with suspected VTE and the need to protect staff and conserve personal protective equipment, many hospitals were forced to develop guidelines to prioritize diagnostic imaging for the highest risk patients. This clinical reality led to circumstances in which empiric therapeutic anticoagulation may be considered without radiographic confirmation [3, 4]. Drawing on our clinical experiences, we hypothesized that many patients with COVID-19 were treated for VTE without a confirmatory diagnostic test, changing the certainty of the diagnosis, potentially misclassifying patients as having VTE who did not. This fact will cause important new challenges for researchers using national registries and databases to investigate VTE in patients with COVID-19. For example, many studies of VTE in patients with COVID19 require VTE confirmation by duplex or CT scan [5, 6]. This study sought to determine the proportion of patients with COVID-19 empirically treated for VTE without diagnostic imaging.