It will be conducted by a team of scientists and clinicians looking into why some people with DVT are more likely to have it more than once.

The team has identified for the first time abnormal blood clot structures in some patients who are apparently being effectively treated with Warfarin.

These patients have an abnormal, dense clot resistant to anticoagulation treatment – meaning they are more at risk of a recurrent problem.

Now the team has developed a biomarker (a form of blood test) to detect and measure this abnormal structure, which could lead to new treatment regimes in the future.

A pilot study has been carried out and will be followed by more detailed research involving upwards of 700 patients with DVT.

The work is being carried out at the Haemostasis Biomedical Research Unit (HBRU), based at Morriston Hospital and led by its founder, emergency medicine consultant Professor Adrian Evans.

He said: “Our new findings give us more understanding why certain people fail to respond to treatment.

“These patients have abnormal architecture in their clots. It is different in structure to other patients who are fully anti-coagulated for other conditions such as atrial fibrillation.”

The latest significant findings have now been published in the prestigious British Journal of Haematology, building on the team’s previous published research.

The HBRU is a partnership between ABMU, Swansea University – involving the Colleges of Engineering and Medicine – together with industry.

It investigates new biomarkers that could provide clinicians with more effective means of screening patients at risk of blood clot-related conditions such as stroke.

If the patients are already ill, biomarkers can help with the diagnosis of the disease and its severity, and monitor the effectiveness of treatments.

Following a £1.5 million award by the National Institute of Social Care and Health Research in 2010, the team undertook a research programme looking at seven diseases, involving the recruitment of 1,300 patients.

They discovered that people with DVT who did not respond to treatment had abnormal clotting properties that could be associated with recurring events.

DVT is a blood clot in one of the deep veins in the body, usually in the larger vein running through the calf muscles and the thigh.

It can cause pain and swelling and could lead to a pulmonary embolism.

Around one in every 1,000 people in the UK is affected by DVT each year. Risk factors can include a family history of blood clots, medical conditions including cancer and heart failure, and being overweight or obese.

The pilot DVT study looked at 150 patients, while the detailed research will involve upwards of 700 people from across the ABMU area.

It is being funded by a £1.2 million Healthcare Impact Award by the Engineering and Physical Sciences Research Council.

When patients first arrive with DVT in hospital they will have a blood test using the new biomarker before they start treatment. They will then be followed up over a period of years to see if they have recurrent episodes.

Professor Evans said he hoped the larger study would start in around a year’s time, or possibly sooner, and last between three and five years.

He added: “Now we know we can detect and measure these abnormal structures using our new biomarker we may be able to reassess and target a new treatment regime in the future.

“We have received further funding to discover why people develop these abnormal clots which are resistant to current treatment.

“It is still early days but this discovery has made significant inroads into our understanding of why some people respond to treatment and some don’t.”

Professor Rhodri Williams, Professor of Complex Fluids at Swansea University’s School of Engineering, has been working with Professor Evans for 10 years to develop new biomarkers of abnormal clot microstructure. He said: “The recent paper from the group, published in the British Journal of Haematology, is a landmark in our development of new biomarkers for abnormal clotting.

“It establishes the value of our research in terms of its clinical translation and application to patients.”

This is an ABMU Health Board news release.