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Effect of anticoagulant therapy in COVID-19 patients
R G Tieleman1, F A Klok2, E Belfroid3
1Department of Cardiology, Martini Hospital, Groningen, The Netherlands. r.tieleman@mzh.nl.
Insights
Anticoagulation therapy in COVID-19 patients shows insufficient evidence for improved outcomes or reduced thromboembolic events. More high-quality randomized controlled trials are needed to determine its true clinical effectiveness.
Area of Science:
- Cardiovascular Medicine
- Infectious Diseases
- Pharmacology
Background:
- COVID-19 is associated with an increased incidence of thromboembolic events.
- The efficacy of anticoagulation in preventing these complications and improving outcomes in hospitalized COVID-19 patients remains unclear.
Purpose of the Study:
- To systematically review the effect of prophylactic and therapeutic anticoagulation on cardiovascular and thromboembolic complications in COVID-19 patients.
- To assess the impact of anticoagulation on clinical outcomes, including mortality, hospital admission, and need for mechanical ventilation.
Main Methods:
- A systematic literature search was conducted on Medline and Embase databases until July 17, 2020.
- Eight studies were included in the analysis, stratified by the timing of anticoagulation initiation (before or during hospitalization).
- Outcome measures included mortality, hospital admission, length of stay, thromboembolic events, mechanical ventilation, and acute kidney injury.
Main Results:
- Insufficient evidence suggests therapeutic anticoagulation improves outcomes in COVID-19 patients; only one small study showed improved mortality.
- No significant positive effects of anticoagulation were observed on other outcome measures, except for a potential reduction in pulmonary embolism in two studies.
- The overall quality of evidence across all included studies was low to very low, according to GRADE methodology.
Conclusions:
- Current evidence is insufficient to establish the benefit of anticoagulation for COVID-19 patients due to the low quality of available studies.
- High-quality randomized controlled trials are essential to definitively answer whether anticoagulation improves outcomes in COVID-19.
Background:
In patients hospitalised with COVID-19, an increased incidence of thromboembolic events, such as pulmonary embolism, deep vein thrombosis and stroke, has been reported. It is unknown whether anticoagulation can prevent these complications and improve outcome.
Methods:
A systematic literature search was performed to answer the question: What is the effect of (prophylactic and therapeutic dose) anticoagulation therapy in COVID-19 patients on cardiovascular and thromboembolic complications and clinical outcome? Relevant outcome measures were mortality (crucial), hospital admission, length of stay, thromboembolic complications (pulmonary embolism, stroke, transient ischaemic attack), need for mechanical ventilation, acute kidney injury and use of renal replacement therapy. Medline and Embase databases were searched with relevant search terms until 17 July 2020. After systematic analysis, eight studies were included. Analysis was stratified for the start of anticoagulation before or during hospital admission.
Results:
There was insufficient evidence that therapeutic anticoagulation could improve the outcome in patients hospitalised with COVID-19. None of the studies demonstrated improved mortality, except for one very small Italian study. Furthermore, none of the studies showed a positive effect of anticoagulation on other outcome measures in COVID-19, such as ICU admission, length of hospital stay, thromboembolic complications, need for mechanical ventilation, acute kidney failure or need for renal replacement therapy, except for two studies demonstrating an association between anticoagulation and a lower incidence of pulmonary embolism. However, the level of evidence of all studies varied from 'low' to 'very low', according to the GRADE methodology.
Conclusion:
Analysis of the literature showed that there was insufficient evidence to answer our objective on the effect of anticoagulation on outcome in COVID-19 patients, especially due to the low scientific quality of the described studies. Randomised controlled studies are needed to answer this question.
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