Study finds ‘high rate’ of blood clots among Covid-19 hospital patients

A “significant percentage” of patients admitted to hospital with Covid-19 had blood clots in their lungs, a study has revealed.

Research carried out by a team at the Brighton and Sussex Medical School (BSMS) has found infection caused by the new coronavirus to be associated with a high incidence of venous thromboembolism, a condition in which a blood clot forms in the deep veins of the leg, groin or arm and can travel to the lungs, leading to pulmonary embolism.

Of the 274 consecutive cases of Covid-19 admitted to hospital, 21 (7.7%) were diagnosed with venous thromboembolism.

Blood clot on the lungs was seen in 16 (76.2%) of these cases.

The study, published in the Clinical Medicine Journal, was carried out at the Brighton and Sussex University Hospitals NHS Trust, including two acute hospital sites in southern England.

The team said a type of test known as D-dimer blood test, which looks for tiny protein fragments that form when a blood clot dissolves in the body, was useful in identifying patients at highest risk of venous thromboembolism.

Lead author Dr Chi Eziefula, a senior lecturer in infection at BSMS, said: “Identifying which patients have a risk of, and clinical evidence of, a venous thromboembolism in Covid-19 is highly important for two reasons.

“Firstly, because venous thromboembolism is linked to a risk of death, and secondly because it is treatable with anticoagulant medications.”

The researchers are calling for urgent clinical trials to see if anticoagulants, medicines that help prevent blood clots, could help in preventing deaths from Covid-19 infection.

Dr Tim Chevassut, a reader in haematology at BSMS and one of the study authors, said: “This study signals the importance of further research to explore the pathological mechanisms specific to Covid-19.

“It also highlights the urgent need for clinical trials to evaluate the role of anticoagulation treatment for the prevention of deaths and morbidity from Covid-19 infection.”

The findings come after another recent study by experts at Royal Brompton Hospital revealed that blood-thinning drugs could help save the lives of Covid-19 patients.

However, they said a blanket use of anticoagulants would not be appropriate and that any treatment would have to start very early to prevent clots forming.