Should therapeutic dose anticoagulation be empirically used in COVID-19 patients requiring ICU level care (i.e., in the absence of confirmed or suspected VTE)?
Microvascular thrombosis is hypothesized to be involved in hypoxemic respiratory failure in some patients with COVID-19. Autopsy studies show large vessel and microvascular thrombosis, pulmonary hemorrhage and high prevalence of VTE. Although retrospective cohort studies of patients treated or not treated with therapeutic anticoagulation have been published, such observational data should not be used to support changes in practice due to survivor bias, confounding by indication, and lack of adjustment for important patient comorbidities and other treatments.
Recently, enrollment of patients requiring ICU level of care in the 3 ongoing multiplatform trials (REMAP-CAP, ATTACC and ACTIV-4A) was paused (as of December 21, 2020) due to an interim pooled analysis demonstrating futility of therapeutic-intensity anticoagulation in reducing the need for organ support over the first 21 days compared with standard-intensity prophylaxis in this
specific subgroup. ICU level of care and organ support were defined as requiring high flow nasal oxygen, invasive or noninvasive mechanical ventilation, vasopressor therapy, or ECMO support. Additional outcomes have not yet been reported. This FAQ will be updated as more information becomes available. Enrollment in these three trials is continuing for patients who require hospitalization but do not require an ICU level of care at time of enrollment. Patients who require therapeutic anticoagulation for other indications are not enrolled in these trials.
Consequently, we discourage the empiric use of therapeutic-intensity heparin or LMWH in COVID-19 patients with no other indication for therapeutic anticoagulation, outside a clinical trial. Patients should be given therapeutic anticoagulation only as otherwise indicated. We recommend participation in
ongoing clinical trials and epidemiologic studies.
COVID-19 and VTE-Anticoagulation
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