British plot coup of the heart valves

Three universities are collaborating on a Pounds 1 million project to create an artificial heart valve that could transform cardiac surgery.

Patients whose diseased heart valves have to be replaced are at present fitted with either a biological or mechanical valve.

The biological type, usually grafted from pigs, degenerates over time and has to be replaced. The mechanical type induces blood clotting, and patients have to take anticoagulants for the rest of their life, which can cause side-effects ranging from nosebleeds to strokes.

Both valves work equally well, and the age of the patient normally determines which type is fitted: the biological valve avoids the need for extra drugs, but it has a lifespan of under ten years, deteriorating even more quickly in young people, who would then have to undergo further operations.

Glasgow, Liverpool and Leeds universities are working together on a three-year project to find a long-lasting valve that does not require lifelong medication.

David Wheatley, professor of cardiac surgery at Glasgow University, who is leading the research, said: "Anticoagulants are often either impractical or associated with a very high complication rate."

In countries with inadequate health care, young people with artificial heart valves had a high risk of fatal complications, he said. But even in Britain, where the National Health Service carries out around 7,000 valve implants a year, it was a drawback to have patients on permanent anticoagulation.

"A valve that doesn't clot would be a very big advance. We're hoping to get the best of biological valves with the durability of mechanical valves. People have been looking for this ever since the first heart valves were designed, but advances in materials and design make it more than likely that we will achieve what we want."

The Leeds group, headed by John Fisher, professor of mechanical engineering, has been extensively involved in developing biological and polyurethane heart valves, while David Williams, head of Liverpool's department of clinical engineering, is an international authority on biomaterials science, and particularly biocompatibility, the ability of biomaterials to function within the body without causing injury.

The Pounds 1 million funding has been awarded under the Government's MedLINK programme. Half will come from the Department of Health and the Physical Sciences Research Council, the remainder coming from AorTech Europe, a Lanarkshire medical company. If the research is successful, it would challenge the current American domination of the heart valve market.