Abstract 14420: Role of Thromboprophylaxis in Outpatients With COVID-19: A Meta-Analysis of Randomized Controlled Trials

Introduction: COVID-19 has been known to cause a hypercoagulable state, leading to venous and arterial thromboembolism. While thromboprophylaxis with anticoagulation (AC) agents is beneficial in hospitalized patients, their role is unclear in outpatients with COVID-19. We conducted a meta-analysis to assess the potential role of AC in outpatients with COVID-19.

Methods: Multiple online databases were searched for randomized clinical trials (RCTs) comparing prophylactic AC to placebo in patients presenting in the outpatient setting with COVID-19. The primary outcomes of interest were hospitalization, death, venous thromboembolism (VTE) and bleeding at the longest available follow up. A random-effects model was used to estimate pooled risk ratios (RR) and 95% confidence intervals (CI).

Results: Four RCTs with a total of 1,464 patients (AC group n=726, placebo group n=738) were included. The mean age was 55 years, 48% of patients were men and the mean duration of follow up was 65 days. Both groups had similar risk of hospitalization (RR 0.93, 95% CI 0.56-1.53, p = 0.76) (Figure 1), death (RR 1.09, 95% CI 0.07-17.14, p = 0.95), VTE (RR 0.35, 95% CI 0.08-1.49, p = 0.16) (Figure 2), and bleeding (RR 1.99, 95% CI 0.73-5.40, p = 0.18).

Conclusions: Thromboprophylaxis with AC in outpatients with COVID-19 is not associated with reduction in the risk of hospitalization, death or VTE when compared with placebo.