Prophylactic anticoagulants for hospitalized COVID‐19 patients (search up to 14 April 2021)

Added April 25, 2022

Citation: Flumignan RLG, Civile VT, Tinôco JD, et al. Anticoagulants for people hospitalised with COVID-19. Cochrane Database of Systematic Reviews. 2022;(3):CD013739.

Language: Abstract available in EN / ES / FA / FR / PT. Plain language summary available in EN / ES / FA / FR / PT / RU / ZH. Full text available in EN. Podcast available in EN here.

Free to view: Yes.

Funding: The authors of this review did not report any external sources of support for this review.

What is this? Some COVID-19 patients develop blood clots in their veins or arteries. Anticoagulants have been suggested as a way to preventing these blood clots.

In this updated Cochrane review, the authors searched for randomized and quasi-randomized trials and cohort studies that compared prophylactic anticoagulants versus active comparators, placebo or no intervention to prevent blood clots in hospitalized COVID-19 patients. They did not restrict their searches by date, language or type of publication and did the most recent search on 14 April 2021. They included 4 randomized trials (4647 patients) of higher versus lower dose anticoagulants and 3 prospective non-randomized studies (11,538 patients) of anticoagulants versus no anticoagulants. They also identified an additional 60 ongoing randomized trials, with more than 35,000 participants.

What was found: At the time of this review, the included non-randomized studies provided very low certainty evidence that the use of anticoagulants rather than no such treatment may reduce all‐cause mortality.

At the time of this review, the included randomized trials showed that higher‐dose anticoagulants result in little or no difference in all‐cause mortality and increase minor bleeding compared to lower‐dose anticoagulants up to 30 days (high certainty evidence), and that higher‐dose anticoagulants probably reduce pulmonary embolism and slightly increase major bleeding compared to lower‐dose anticoagulants in the same time period (moderate certainty evidence).

Implications: The authors of this review stated that they are very confident that new randomized trials will not change their conclusions about the differences between higher and lower dose anticoagulants on all‐cause mortality, minor and major bleeding and pulmonary embolism. However, they concluded that high‐quality randomized trials of difference doses of anticoagulant for people hospitalized with COVID‐19 are needed for other main outcomes (including the need for additional respiratory support) and for the comparison with no anticoagulation.

Other considerations: The authors of this review discussed their findings in the context of place of residence.


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