The incidence of venous thromboembolism (VTE) events in patients with COVID-19 treated with a standard thromboprophylaxis dose of anticoagulants remains high. We conducted a systematic review in order to explore the association between therapeutic-dose anticoagulation and its effect on mortality in patients with COVID-19. A systematic search was carried out using the electronic databases of PubMed, EuropePMC, and the Cochrane Central Database, using specific keywords. All articles that fulfilled the inclusion criteria were included in the qualitative analysis. There were 8 observational studies included in the final qualitative analysis. Quality assessment using the Newcastle-Ottawa Scale (NOS) showed a mean score of 7.5 ± 1.06, indicating moderate to high quality of the studies. Three retrospective cohort studies reported a reduction in the mortality rate, while 6 other studies showed no mortality benefits among patients with COVID-19 treated with therapeutic-dose anticoagulation. There was a slight tendency toward a reduction in the mortality rate among mechanically-ventilated patients with COVID-19 receiving therapeutic-dose anticoagulation. Bleeding events and thrombotic complications among patients receiving therapeutic-dose anticoagulation were reported in 3 studies. Although it is too soon to draw any conclusions, this systematic review draws attention to current evidence regarding the association between therapeutic-dose anticoagulation and its effect on mortality in patients with COVID-19.
The data from these observational studies have such a high risk of bias that we really don't know the answer until we have the results of the many RCTs going on.
This is an informative summary of information to date; although, with the rapidly increasing body of literature on this topic, has the unfortunate potential to become outdated quickly.