A new Irish study has found that blood clotting is a significant cause of death among some patients with COVID-19.

According to the findings, Irish patients admitted to hospital with severe COVID-19 infection are experiencing abnormal blood clotting that has contributed to the death of some.

The study was carried out by researchers at the Irish Centre for Vascular Biology at the Royal College of Surgeons in Ireland (RCSI), St James's Hospital in Dublin and Trinity College Dublin.

They found that abnormal clotting occurs in patients with severe COVID-19 and this causes micro-clots within the lungs. They also found that those with higher levels of blood clotting activity had a much worse prognosis and were more likely to have to be admitted to ICU.

"Our novel findings demonstrate that COVID-19 is associated with a unique type of blood clotting disorder that is primarily focussed within the lungs and which undoubtedly contributes to the high levels of mortality being seen in patients with COVID-19.

"In addition to pneumonia affecting the small air sacs within the lungs, we are also finding hundreds of small blood clots throughout the lungs. This scenario is not seen with other types of lung infection, and explains why blood oxygen levels fall dramatically in severe COVID-19 infection," explained Prof James O'Donnell, a consultant haematologist at St James's Hospital and director of the RCSI's Irish Centre for Vascular Biology.

He said that understanding how these micro-clots are formed within the lungs "is critical", so that more effective treatments for patients can be developed.

"Further studies will be required to investigate whether different blood thinning treatments may have a role in selected high-risk patients in order to reduce the risk of clot formation," Prof O'Donnell noted.

Emerging evidence also shows that this abnormal clotting problem associated with COVID-19 results in a significantly increased risk of heart attacks and strokes.

Further research on these findings is set to continue as part of a study that has been jointly funded by the Health Research Board and the Irish Research Council, as part of the Government's COVID-19 Rapid Response Research Funding.

Details of these latest findings are published in the British Journal of Haematology.