17% of hospitalized patients with COVID-19 may develop venous thrombosis

Deep vein thrombosis occurs when a blood clot, a thrombus, forms in one or more deep veins in the body, usually on the legs. It can cause pain or swelling in the legs, but it can also occur without symptoms. Following the advancement of the spread of the coronavirus around the world and the conduct of more scientific research to understand what it is and what impact it has on the human body, COVID-19 disease has been found to increase the risk of infected people developing complications with thrombosis.

Italian scientists have started to analyze studies on the association between thrombi and COVID-19. They published this week in the magazine Cardiovascular Surgery Journal the largest review of the scientific literature to date after an 18-month pandemic. The coronavirus has already affected more than 229 million people, and caused the death of more than 4.7 million people around the world, according to the results of the World Health Organization.

It is known that deep vein thrombosis can develop if a person suffers from certain diseases that affect the way the blood clots. A blood clot in the legs can also occur if the person does not move for a long time, for example, after surgery or an accident, when they walk long distances while sitting or when they are in bed.

Venous thrombosis can be very serious because blood clots that occur in the veins can break off and travel through the bloodstream and get stuck in the lungs, blocking blood flow.

Coronavirus infection is a disease, eminently respiratory, but multisystemic since it affects many organs and systems. This is the case with circulatory system it has therefore been associated with the onset of thrombosis and other problems.

Italian researchers, led by Daniela Mazzaccaro, from the vascular surgery operating unit of the polyclinic of San Donato, together with colleagues from the University of Milan, searched for published studies and found a total of 877 results. After the full-text evaluation, 69 articles were included in the qualitative analysis and 23 of them were used for quantitative evaluation. These investigations include the cases of 106,838 patients hospitalized for Covid-19 between January and December 2020.

When analyzing studies, The reported combined prevalence rate of venous thrombosis in COVID-19 patients was found to be 17%. It is much higher for patients who have had to be admitted to intensive care units. In these cases, the rate varies between 60.8 and 85.4%. Venous thrombosis events have been reported in approximately 75% of cases in the popliteal and calf veins. Signs and symptoms were present in 6.1% of cases.

In quantitative evaluation, Factors such as advanced age or obesity increase the risk of venous thrombosis. The female sex shows a greater tendency to its development.

“In patients hospitalized for Covid-19, venous thrombosis is a relatively common finding, with higher prevalence rates in patients admitted to intensive care units,” the Italian researchers wrote in the book. “In patients hospitalized for Covid-19, venous thrombosis is a relatively common finding, with higher prevalence rates in patients admitted to intensive care. Venous thrombosis occurs mainly in the distal regions of the lower limb and is asymptomatic in most cases, ”the review authors concluded.

Other recent work on thrombosis has been done by Irish scientific researchers. They identified how and why some COVID-19 patients can develop clots, a breakthrough that could promote specific therapies to prevent them.

The work was led by researchers at RCSI University of Medicine and Health Sciences, Dublin and has been published in the trade journal Journal of Thrombosis and Haemostasis. He focused on the complications of COVID-19 that often affect the lungs and airways. People with diabetes, high blood pressure, or pre-existing heart problems are at a higher risk of complications with blood clots if they contract the coronavirus.

To understand why these clots occur, the researchers analyzed blood samples taken from Covid-19 patients in the intensive care unit at Beaumont Hospital in Dublin. They found that the balance between a molecule that causes clotting, called von Willebrand factor (VWF), and its regulator, called ADAMTS13, is severely altered in patients with severe COVID-19.

Compared to control groups, the blood of Covid-19 patients exhibited higher levels of VWF procoagulant molecules and lower levels of ADAMTS13 anticoagulant. In addition, the researchers identified other protein changes that caused the reduction in ADAMTS13.

The work was funded by the Irish COVID-19 Vasculopathy Study (ICVS) through the Health Research Board’s COVID-19 Rapid Response Award, as well as a philanthropic grant from the 3M Foundation to the University of Medicine and RCSI Health Sciences in Support of COVID- 19 Research.

“Our research is helping to understand the mechanisms that cause severe blood clots in COVID-19 patients, which is essential for developing more effective treatments. “ said Dr Jamie O’Sullivan, lead author of the study and research professor at the Irish Center for Vascular Biology and the College of Pharmacy and Biomolecular Sciences at RCSI.

“While more research is needed to determine whether targets to correct ADAMTS13 and VWF levels can be a successful therapeutic intervention, it is important that we continue to develop therapies for Covid-19 patients. Vaccines against Covid-19 will continue to be unavailable to many people around the world, and it is important that we provide effective treatments to them and to those suffering from last-minute infections, ”he said. he declares.

“COVID-19 hospital patients are at greater risk of developing thrombosis, which is the formation of blood clots primarily in the legs. In some cases, these clots can migrate to the lungs. At the start of the pandemic, some studies were conducted to assess whether anticoagulation improved mortality, but it has not shown that it is effective. Today, with the knowledge acquired throughout the world, only prophylaxis or anticoagulants are administered in low doses to prevent the formation of thrombi. When thrombosis is suspected, a Doppler examination of the lower limbs is performed. If pulmonary thromboembolism is suspected, contrast tomography or angiography is indicated, ”he explained to Infobae Dr Carina Balasini, intensive care specialist and member of the board of directors of the Argentine Society of Intensive Care (SATI).

Besides, Dr Balasini commented that most hospital patients are given a small dose of anticoagulants – usually sodium or low molecular weight heparin – to prevent thrombus formation in patients’ internal limbs due to the immobile position. . This dose is administered to all patients in intensive care with any pathology. In other patients, who cannot receive heparin, pneumatic boots are installed to improve venous circulation.

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