Therapeutic Anticoagulation in Critically Ill Patients with Covid-19 – Preliminary Report

In patients with severe Covid-19, therapeutic anticoagulation did not improve hospital survival or days free of organ support compared to usual care pharmacological thromboprophylaxis.

Background
Thrombosis may contribute to morbidity and mortality in Covid-19. We hypothesized that
therapeutic anticoagulation would improve outcomes in critically ill patients with Covid-19.

Methods
We conducted an open-label, adaptive, multiplatform, randomized, clinical trial. Patients with
severe Covid-19, defined as the requirement for organ support with high flow nasal cannula,
non-invasive ventilation, invasive ventilation, vasopressors, or inotropes, were randomized to
receive therapeutic anticoagulation with heparin or pharmacological thromboprophylaxis as
per local usual care. The primary outcome was an ordinal scale combining in-hospital mortality
(assigned –1) and days free of organ support to day 21.

Results
Therapeutic anticoagulation met the pre-defined criteria for futility in patients with severe
Covid-19. The primary outcome was available for 1,074 participants (529 randomized to
therapeutic anticoagulation and 545 randomized to usual care pharmacological
thromboprophylaxis). Median organ support-free days were 3 days (interquartile range –1, 16)
in patients assigned to therapeutic anticoagulation and 5 days (interquartile range –1, 16) in
patients assigned to usual care pharmacological thromboprophylaxis (adjusted odds ratio 0.87,
95% credible interval (CrI) 0.70-1.08, posterior probability of futility [odds ratio<1.2] 99.8%).
Hospital survival was comparable between groups (64.3% vs. 65.3%, adjusted odds ratio 0.88,
95% CrI 0.67-1.16). Major bleeding occurred in 3.1% of patients assigned to therapeutic
anticoagulation and 2.4% of patients assigned to usual care pharmacological
thromboprophylaxis.