New insights on COVID-associated blood clots in people with inherited thrombotic conditions

Red blood cells

With venous blood clots far more common with COVID-19 infection than vaccines, new information is emerging on the association between COVID-associated blood clots in people with inherited thrombotic conditions such as the common Factor V Leiden, which impacts about in one in every 20 or 25 people in Australia.

A paper published in Circulation by researchers from the Baker Heart and Diabetes Institute highlights that genetic thrombotic conditions, including the Factor V Leiden mutation, are indeed associated with a higher risk of COVID-19 venous thromboembolism (a blood clot that starts in the vein), and could be useful in assessing risk of developing blood clots during COVID-19 infection.

A large cohort was studied from the UK Biobank, with more than 13,712 individuals aged 45-69 years and who subsequently tested positive to COVID-19 between January 2020 and May 2021 included in the study. COVID-19 venous thromboembolism (VTE) was identified in 197 cases and there were 890 deaths from COVID-19, with COVID-19 VTE associated with higher COVID-19 deaths.

Researchers and haematologists, Drs Hannah Stevens and Associate Professor James McFadyen believe the identification of novel risk factors, such as genetic thrombophilias, may help to stratify patients with a higher risk of developing COVID-19 associated blood clots.

They say all patients with COVID-19 admitted to hospitals receive medication to prevent blood clots, so this study may help identify a group of patients who need higher dose blood thinner medications.

With significant interest in the optimal dose and duration of blood thinner medications for the prevention of COVID-19 thrombotic complications, they say this is another important piece in the puzzle.

With blood clots caused by COVID-19 already associated with a higher risk of death, it important to understand vulnerable groups and how best to treat them.

They are also involved in clinical trials to understand more. Associate Professor McFadyen is involved in the ASCOT clinical trial that aims to generate clinical evidence about new treatments for COVID-19 to reduce death or the need for mechanical ventilation in hospitalised patients. This includes investigating anticoagulation therapies which aim to reduce the risk of blood clots associated with the COVID-19 infection.

/Baker Institute Public Release. View in full here.