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Anticoagulation Among Patients Hospitalized for COVID-19: A Systematic Review and Prospective Meta-analysis

  • The WHO Rapid Evidence Appraisal for COVID-19 Therapies (REACT) Working Group

    Research output: Contribution to journalReview articlepeer-review

    Abstract

    Background: Reported results of clinical trials assessing higher-dose anticoagulation in patients hospitalized for COVID-19 have been inconsistent.

    Purpose: To estimate the association of higher- versus lower-dose anticoagulation with clinical outcomes.

    Data Sources: Randomized trials were identified from the World Health Organization's International Clinical Trials Registry Platform and ClinicalTrials.gov with no restriction by trial status or language.

    Study Selection: Eligible randomized trials assigned patients hospitalized for COVID-19 to higher- versus lower-dose anticoagulation.

    Data Extraction: 20 eligible trials provided data in a prospectively agreed format. Two further studies were included based on published data. The primary outcome was all-cause mortality 28 days after randomization. Secondary outcomes were progression to invasive mechanical ventilation or death, thromboembolic events, and major bleeding.

    Data Synthesis: Therapeutic- compared with prophylactic-dose anticoagulation with heparins reduced 28-day mortality (OR, 0.77 [95% CI, 0.64 to 0.93]; 2 = 29%; 11 trials, 6297 patients, of whom 5456 required low or no oxygen at randomization). The ORs for 28-day mortality were 1.21 (CI, 0.93 to 1.58; I 2 = 0%) for therapeutic-dose compared with intermediate-dose anticoagulation (6 trials, 1803 patients, 843 receiving noninvasive ventilation at randomization) and 0.95 (CI, 0.76 to 1.19; I 2 = 0%; 10 trials, 3897 patients, 2935 receiving no or low oxygen at randomization) for intermediate- versus prophylactic-dose anticoagulation. Treatment effects appeared broadly consistent across predefined patient subgroups, although some analyses were limited in power. Higher- compared with lower-dose anticoagulation was associated with fewer thromboembolic events, but a greater risk for major bleeding.

    Conclusion: Therapeutic-dose compared with prophylactic-dose anticoagulation reduced 28-day mortality. Mortality was similar for intermediate-dose compared with prophylactic-dose anticoagulation and higher for therapeutic-dose compared with intermediate-dose anticoagulation, although this comparison was not estimated precisely.
    Original languageEnglish
    Pages (from-to)59-69
    Number of pages11
    JournalAnnals of Internal Medicine
    Volume178
    Issue number1
    Early online date24 Dec 2024
    DOIs
    Publication statusPublished - Jan 2025

    Bibliographical note

    Publisher Copyright:
    © 2025 American College of Physicians. All rights reserved.

    Funding

    The WHO contributed to the design and conduct of the study by convening the WHO COVID-19 Clinical Management and Characterization Working Group. This group assembled information on ongoing trials and invited trial investigators to participate in this prospective meta-analysis. The WHO chief scientist invited trial investigators to participate and provided a secure portal for submission of data. Funding for administrative and communications support was provided by the World Health Organization.

    Funders
    World Health Organization

      UN SDGs

      This output contributes to the following UN Sustainable Development Goals (SDGs)

      1. SDG 3 - Good Health and Well-being
        SDG 3 Good Health and Well-being

      Keywords

      • Anticoagulants
      • Cardiology and cardiovascular diseases
      • Clinical trials
      • COVID-19
      • Hemorrhage
      • Hospital medicine
      • Mortality
      • Prophylaxis
      • Randomized trials
      • Vascular medicine

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