Two studies support the use of balloon angioplasty to treat dangerously narrowed heart arteries.

The latest evidence is that a combination of angioplasty and clot-busting drug sharply reduced the likelihood of heart attack and death.

Smoking, poor diet, diabetes, and lack of exercise can all contribute to hardened and narrowed heart arteries.

If the blood flow is interrupted, the muscles of the heart may not get enough oxygen and this can cause a heart attack or other problems such as angina.

Balloon goes up

Angioplasty involves inserting a balloon into the artery, inflating it to widen the blood vessel.

Then, a mesh known as a stent is placed in the artery to stop it closing up again.

The research, published in the New England Journal of Medicine, found that this procedure - balloon and stent - combined with the drug abciximab, reduced the chance of heart attack by almost 50%.

The rate of heart attack was slightly higher if only the balloon treatment and drug were given.

Angioplasty more effective

Other research compared the worth of angioplasty against using only a clot-busting drug, finding that elderly heart-attack patients given angioplasty fared better.

US researchers studied death rates among 20,683 heart-attack victims who arrived at hospital within 12 hours of the symptoms starting.

Angioplasty patients, who had a balloon inserted then inflated inside the constricted coronary arteries, had a 27% lower risk of death after one year, compared to those given drugs designed to dissolve clots blocking the blood vessels.

But when the study was narrowed to those patients who obviously benefited from each procedure, the difference was much reduced.

The study appeared in the Journal of the American Medical Association.