Recent studies indicate that the administration of anticoagulants can significantly decrease complications and mortality caused by COVID-19.
While waiting to immunize a large part of the population with the recently developed vaccines against COVID-19, we must resign ourselves to having to deal with the disease for a few more months. Inevitably, many people will become ill during this time and so it is important to keep looking for new approaches to reduce serious complications from the infection.
Blood clots
One of the main characteristics of COVID-19 is that it is very often the body’s maladaptive response to the virus that is responsible for severe forms of the disease rather than the virus itself. In a large proportion of severely ill patients, there is in particular a disproportionate inflammatory response that damages vital organs and can cause rapid deterioration in health.
Another consequence of this inflammatory shock is to cause an abnormal formation of clots (thromboses) which block the arrival of blood to vital organs (lungs, heart, brain, kidney) and can cause several serious accidents (heart attack, stroke, pulmonary embolism). , kidney failure) which increase the risk of death. For example, autopsies performed on patients who died of COVID-19 revealed the presence of a multitude of clots in the blood microvessels supplying the heart (capillaries, arterioles), causing several areas of necrosis in the heart tissue. (1).
A systematic analysis of several organs infected with the virus suggests that this hypercoagulability is caused by significant disturbances of several proteins essential for the balance of the coagulation cascade, in particular prothrombin and factors XI, XII and XIIIa (2).
Prevent clots
The importance of these clots in the development of complications from COVID-19 is demonstrated by a recent study, carried out on 4297 patients, indicating that the use of anticoagulants such as heparin provides important benefits for patients. patients with COVID-19 (3).
The researchers observed that the administration of heparin in the first 24 hours after admission was associated with a 27% reduction in the risk of mortality in the month following hospitalization.
The results of three clinical trials carried out in more than 300 hospitals worldwide point in the same direction and suggest that the administration of heparin could significantly reduce the risk of complications and death from COVID-19 (4).
Compared to standard treatment routinely used to prevent clots in hospitalized patients (half dose of heparin), it was observed that in patients with moderate form of COVID-19 (hospitalized, but not in intensive care and without mechanical ventilation), full-dose heparin treatment reduced the risk of mechanical ventilation by approximately 30% (16 vs 23% of patients) and the risk of mortality by 25% (5.7 vs 7.7 %).
This beneficial effect of anticoagulation is, however, observed only in moderately ill patients: another part of the study found that administration of full doses of heparin in those who are in intensive care and require mechanical ventilation at otherwise resulted in a deterioration of their clinical condition.
Establishing very precise clinical protocols will therefore be essential to maximize the benefits of anticoagulant therapy.
Better care
These results show that even in the absence of specific antiviral drugs, we are still making significant progress in the treatment of COVID-19.
In addition to the anticoagulants mentioned above, drugs (corticosteroids) that control the excessive inflammatory response generated in response to the virus have also been shown to reduce mortality in hospitalized patients by around 30%. (5).
By specifically targeting two major phenomena disrupted by coronavirus infection (inflammation and coagulation), these two approaches will therefore save many lives by the time we reach a sufficient degree of immunization. to negate rates of infection with the virus.
♦ (1) Pellegrini D et al. Microthrombi as a major cause of cardiac injury in COVID-19: a pathologic study. Circulation, published on January 22, 2021.
♦ (2) 10 Nic et coll. Multi-organ proteomic landscape of COVID-19 autopsies. Cell 2021; 184: 775-791.e14.
♦ (3) Rentsch CT et coll. Early initiation of prophylactic anticoagulation for prevention of coronavirus disease 2019 mortality in patients admitted to hospital in the United States: cohort study. BMJ 2021; 372: n311
♦ (4) National Heart, Lung, and blood Institute. Full-dose blood thinners decreased need for life support and improved outcome in hospitalized COVID-19 patients. Press release published on January 22, 2021.
♦ (5) RECOVERY Collaborative Group. Dexamethasone in hospitalized patients with Covid-19 – preliminary Report. N. Engl. J. Med., published July 17, 2020.
–
