Clots can occur not only during infection, but also after discharge from hospital.
Within the framework of World Thrombosis Day, which is commemorated on October 13, the Argentine Group of Hemostasis and Thrombosis (CAHT Group) warns that patients who had Covid-19, after discharge, have an increased risk of develop both arterial and venous thrombosis.
A statement issued by the professional association indicates that various studies report cumulative evidence of thrombosis, including arterial and venous, in 30 days after discharge from hospital, with incidence values of 2.5%, and 0.6% in the case of pulmonary embolism.
“The risk of venous thromboembolism (VTE) associated with hospitalization extends up to 6 weeks after discharge in those patients with high medical risk of presenting this type of thrombotic event. At least 60% of all VTE events in clinically ill patients occurs in the post-discharge period, with the first three weeks being associated with an increase in five times the risk of fatal pulmonary thromboembolism “, affirms the hematologist Miguel Castro Ríos, coordinator of the directive committee of the CAHT Group.
Thrombosis consists of the formation of a blood clot in a blood vessel, vein or artery, which once it occurs can block normal blood flow and even break off and travel to an organ. Venous thromboembolism or VTE is a condition in which blood clots most often form in the deep veins of the legs, known as deep vein thrombosis, or DVT, and can travel in the bloodstream and lodge in the lungs, an event known as pulmonary embolism or PE.
In general, thrombosis is a serious complication that can compromise the evolution of a disease. In particular, in those affected by the SARS-CoV-2 coronavirus, it was seen that the thrombosis and inflammation component plays a very important role in those with poor evolution and, as the patient worsens, the incidence of thrombosis increases.
From the International Society of Thrombosis and Haemostasis (ISTH, for its acronym in English) they highlight that first reports suggest a high incidence of VTE in hospitalized Covid-19 patients. “This appears to be because Covid-19 causes a lot of inflammation, which produces chemicals that lead the liver to produce large amounts of clotting factors, making the blood sticky.”
People admitted to intensive care, they say, have three to six times more likely to experience DVT than a patient in the intensive care unit for any other reason, such as congestive heart failure. And the risk remains long after discharge from the hospital.
“With a simple evaluation, your doctor can determine if you are at risk of thrombosis, decide if you should receive treatment in this regard and avoid complications during your hospitalization,” they emphasize from the ISTH.
“The care of a person with Covid-19 at risk of developing venous thromboembolism includes strategies to prevent clot formation, with measures that can range from anticoagulant medications to mechanical devices (such as compression stockings) and the early mobilization of hospitalized patients “, explains the hematologist Dolores Puente, coordinator of the organizing committee of the CAHT Group’s World Thrombosis Day.
Recent data reveal that in select populations at high risk for VTE, extend the duration of prophylaxis measures for 4 weeks with anticoagulants after hospital discharge offers a net clinical benefit by reducing the risk of thromboembolism. This benefit is more pronounced in those whose hospitalization rate was due to infection, especially pneumonia, a very common condition in hospitalizations for Covid-19.
“Deep vein thrombosis and pulmonary embolism are quite common in the population affected with Covid-19. Even those who have previously developed a thrombosis present an increased risk, so prophylaxis must be even more exhaustive in them, “says Puente.
The medical community, based on the latest available research, supports a score that identifies patients with three times higher risk for VTE and which would obtain a significant benefit with the extension of thromboprophylaxis.
“This finding may be especially relevant to mitigate the degree of commitment in people with Covid-19 at high risk of thromboembolism due to factors such as advanced age, days of hospitalization, cancer or a previous history of VTE, thrombophilia and severe immobility, among other factors. In them, it would be reasonable to use extended thromboprophylaxis for at least 2 and up to 6 weeks after discharge, “adds Castro Ríos.
Health professionals had already reported an unexpected prevalence of blood clotting disturbances among Covid-19 patients, in what could be a perfect storm of potentially fatal risk factors. In fact, the reported rate of thrombosis in hospitalized patients with Covid-19 ranges between 5 and 45% and it is influenced by the degree of severity of the disease and the comorbidities that the patients present.
For Puente “this situation forces the health team to consider different strategies for the management of VTE in patients hospitalized for Covid”.
On the other hand, beyond those who had Covid-19, to reduce the risk of blood clots in those people who by staying longer at home are exposed to poor mobility, the CAHT Group recommended keep active and in those who receive antithrombotic medication, do not stop taking their medications, not even among those with a diagnosis of Covid-19.