The use of direct oral anticoagulants (DOACs) did not reduce the rate of hospitalisation, intensive care admission or fatality due to COVID-19, according to the results of a Swedish observational study, published in The Journal of Internal Medicine.
DOACs are used in the treatment of atrial fibrillation (AF) by preventing blood clots. Even though blood clots are thought to contribute to complications from the new coronavirus infection, users of this class of drug do not seem to be protected against severe COVID-19, according to the registry study from Karolinska Institutet (Solna, Sweden).
Early during the ongoing pandemic, there were reports that many patients with severe COVID-19 had blood clots in their pulmonary arteries and other parts of the body.
“Our hypothesis was that blood clots per se could contribute to the severe functional deterioration of the lungs and other organs that is associated with COVID-19, so one would think that preventative treatment with anticoagulants would provide some protection,” says Benjamin Flam, doctoral student at the Department of Physiology and Pharmacology, Karolinska Institutet, and specialist doctor in anaesthesiology and intensive care at Karolinska University Hospital.
To find out if this was the case, the study team conducted a registry based study of patients on anticoagulant medication for reasons other than COVID-19. The study included over 100,000 Swedes between the ages of 45 and 84 with AF being treated with DOACs. The control groups included over 350,000 individuals with cardiovascular disease who were not on such medication.
The researchers then examined the rates of hospitalisation, intensive care admission and fatality due to COVID-19 between 1 February and 31 May 2020, adjusting for such factors as age, sex, place of residence and other diseases and medication.
The results of the observational study show that DOAC use did not reduce the rate of hospitalisation, intensive care or fatality due to COVID-19.
“Our findings suggest that early DOAC treatment doesn’t protect against severe COVID-19, but these should be treated with caution since there might remain differences between the groups that are difficult to measure,” said Flam. “Also, our study says nothing about whether other types of anticoagulants could be effective, but a good many clinical studies are being done around the world.”