Doctors at Oxford's John Radcliffe Hospital are taking part in heart trials that could save the National Health Service £20m a year.

Cardiologist Dr Adrian Banning is leading the study, which is working with 43 patients suffering from heart disease to see if a new type of equipment, called a stent, can help keep their arteries clear.

If the trial proves successful the number of patients needing additional surgery, including heart bypass operations, could be reduced.

Stents are already used in heart surgery, and are tiny mesh tubes which prop open clogged up coronary arteries, improving blood flow to the heart.

In the UK, 28,000 people undergo the procedure every year.

Nearly one third of these patients, about 8,400, suffer from restenosis -- a further narrowing of the arteries -- despite their treatment. Because of this, many people have to be fitted with new stents, at an average cost of £3,000, or are not even considered for the treatment and have to have a heart bypass instead.

The new stents, being studied in the Taxus II trials in Oxford, are coated with a special drug to prevent arteries from clogging up.

In smaller trials, less than five per cent of patients fitted with the new version suffered restenosis.

This means the new stent has the potential to reduce the number of patients requiring additional procedures from 8,400 to 1,400, with a saving of £21m.

Dr Banning said: "If the results show drug eluding stents to be as effective as I expect, they will transform our practice as many more patients will undergo stent procedures rather than bypass surgery. This would be a greater relative step than the introduction of the stent itself." About 124,000 people die from heart disease in the UK every year.

The patients in the Oxford study are taking part in blind trials, so they do not know whether they are being fitted with the new type of stent.

The trial started in September and is due to finish later this month.