Derriford Hospital joins UK-wide trial to find safest blood-thinning treatment after heart valve surgery

Heart surgery patients at Derriford Hospital in Plymouth are being asked to take part in a national trial that aims to find the safest and most effective blood-thinning treatment after heart valve surgery.

University Hospitals Plymouth NHS Trust is one of 30 cardiac centres across the UK taking part in the AFFECT trial, which is funded by the National Institute for Health and Care Research (NIHR). The study is open and aims to recruit 25 patients in Plymouth, with recruitment due to end on August 31, 2028. Eligible patients will be approached by the study team, who can give them more information.

About 3,000 people in the UK have surgery each year to repair a leaking mitral valve, one of the four valves of the heart. The condition, known as mitral regurgitation, means the valve fails to close tightly, so blood leaks backward into the left atrium instead of pumping forward to the body. It forces the heart to work harder and can lead to fatigue, shortness of breath and potential heart failure.

Patients who also have a heart rhythm problem, known as atrial fibrillation, usually need blood-thinning medication to reduce their risk of a stroke or other complications after surgery.

Current national and international guidelines recommend a vitamin K antagonist such as warfarin. A newer group of medicines, known as direct oral anticoagulants (DOACs), is now also widely used. The trial aims to show which option offers the best long-term outcomes for patients.

Mr Clinton Lloyd, consultant cardiac surgeon and principal investigator for the trial in Plymouth, said: “We are delighted to be participating in the AFFECT trial. Being able to support this important research locally in Plymouth will help us to compare newer direct oral anticoagulants with established treatments such as warfarin, helping to determine which approaches offer the best long-term outcomes and informing future standards of care for patients.”

The study is led by researchers at The James Cook University Hospital in Teesside and supported by cardiac consultants across the UK. The NIHR has awarded it just over £2.1 million, which covers the whole study nationally and not the Plymouth site. It began running from October 2024 and is due to end in May 2030.

Professor Enoch Akowuah, chief investigator for the trial at University Hospitals Tees, said: “This is an important question for both patients and clinicians. We know anticoagulation is essential for patients with atrial fibrillation after mitral valve repair, but we do not yet know which treatment offers the best balance of safety and protection. The AFFECT Trial will provide high-quality evidence to guide national treatment decisions and improve long-term outcomes for patients across the UK and internationally.”