Doctors here will start a trial this month on a new balloon designed to unclog the arteries of heart patients and keep them clear during the critical months after surgery.

The balloon, which was developed in Germany, has shown promise in preventing the arteries from filling with scar tissue in the aftermath of an operation.

From this month, the National Heart Centre will use the new balloon to prevent heart attacks in a trial on 30 patients.

The procedure will involve inserting the tiny balloon capable of delivering an anti-clogging drug into a blocked artery.

This means doctors will no longer need to implant a thin tube of wire mesh coated with the drug, known as the drug-eluting stent, inside the problematic artery.

A study done in 114 patients in Europe showed that 15 per cent of them saw their arteries re-narrow six months after undergoing a procedure with the new balloon, said its author, Dr Martin Unverdorben.

Previous studies have shown the re-narrowing of drug-eluting stents to be about 30 per cent, and that of bare metal stents to be about 50 per cent.

About 15 per cent of the patients who used the new balloon suffered a heart attack or died after six months.

The rate of heart attacks or deaths was 19 per cent for those on drug-eluting stents, and 27 per cent for those on bare metal stents.

Dr Unverdorben, an associate professor of medicine at the Centre for Cardiovascular Diseases' Clinical Research Institute in Germany, said yesterday: "For it to have such significantly lower rates, there must be something there."

He was speaking at a press conference held during a four-day conference of 1,500 cardiologists at the Singapore International Convention and Exhibition Centre that began yesterday.

In the procedure known as angioplasty - usually used to treat heart disease - a balloon borne on a long flexible tube is threaded through the arteries to the blocked area, and then inflated to clear it.

Often, a stent, placed around the balloon earlier, is left behind in the artery to prop it open after the balloon is removed.

The stent is also often coated with a drug that prevents the artery walls from growing too much scar tissue which will clog up the artery again.

But the new balloon will have the drug coated on its own surface instead, and when inflated, will push it onto the artery walls which will absorb it. The balloon will then be removed.

Dr Unverdorben added that the new balloon also appears to be less likely to cause patients to develop blood clots, a potentially fatal complication linked to drug-coated stents that has caused concern in the past two years.

About 0.6 per cent of patients on drug-eluting stents develop blood clots within a year.

But none of the 245 patients in two ongoing studies has developed blood clots more than a year after undergoing a procedure with the new balloon.

And this is despite patients taking a costly blood-thinning drug for just a month, instead of six to 12 months as recommended for patients on drug-eluting stents.

This could save patients here $120 a month, said consultant cardiologist Victor Lim with the National Heart Centre.

German medical device company B. Braun, which makes the new balloon, expects it to be approved by the European authorities in the second or third quarter this year, and to be commercially available here within this year.

Its managing director in Singapore, Mrs Theresa Michelmann-Lim, said that while the new balloon would cost more than a conventional one, the overall cost of the procedure with the new balloon should be comparable to that of a conventional procedure that uses a drug-eluting stent.

An angioplasty here costs about $16,000 to $20,000.


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