Diabetics in the South West are being recruited to help discover why some develop problems after a common type of heart surgery.

Doctors at Derriford Hospital in Plymouth want to find out why patients sometimes develop harmful scar tissue which blocks their arteries.

It can soon build up and lead to a recurrence of angina.

The research programme is seeking to recruit 200 diabetic patients as part of the �250,000 study.

A tiny wire helps open arteries

Diabetics are more likely to have coronary problems requiring angioplasty.

This is a relatively common procedure which opens up arteries which have narrowed, restricting the flow of blood to the heart.

A tiny wire is passed through the body from the wrist all the way to the blockage and then a balloon is inflated to widen the artery again.

A piece of metal mesh, shaped like a pipe, is then inserted in the artery to keep it open.

But a quarter of all diabetics who have this treatment find the artery starts to close up again in time and nobody knows why.

Implants

Dr Joseph Motwani said: "With diabetes, we know there are many abnormalities, including high blood sugar levels and high circulation levels.

"It may be that one or more of these abnormalities contribute to the narrowing appearing in the first place in the coronary artery."

The problem might also be linked to the type of implants used to keep the arteries open.

Patients taking part will have to return for more observations over the next two years.

Diabetes affects about 4% of the population, so the research could benefit many by improving their chances of successful heart surgery.