Researchers hope their findings will lead to new heart disease drugs

Patients with heart disease were given a version of high density lipoprotein (HDL), or "good" cholesterol.

It was found the treatment reduced fatty deposits in their arteries in just a few weeks.

The researchers, writing in the Journal of the American Medical Association, say their small study could lead to a novel way to treat heart disease.

It has opened the door to the future and the development of an entirely new treatment for heart disease Dr Steven Nissen, Cleveland Clinic

The HDL used in the research was based on a natural variant found in a small community in northern Italy, discovered in the 1980s.

The 38 people living in the small Italian community of Limone Sul Garda had a significantly reduced level of heart disease, despite being at high risk.

It was found that they had a mutation of the major protein involved in the formation of HDL cholesterol.

Cholesterol carriers

In the US study 36 patients who had suffered either a heart attack or angina given weekly intravenous transfusions of a synthetic version of this protein, apolipoprotein Milano AI (Apo-AIM). Eleven others were given a dummy version.

Doctors examined patients' arteries using ultrasound scans six weeks after treatment.

In those who had been given the injections, the fatty deposits lining their arteries shrank by an average of one per cent.

In contrast, in patients given dummy injections deposits grew by an average of 0.14%.

This modification could have positive effects in treating patients Professor Sir Charles George, British Heart Foundation

There are two kinds of cholesterol, HDL and low density lipoprotein "bad" cholesterol.

HDL removes cholesterol from arteries and transports it to the liver, but LDL acts in reverse, and deposits cholesterol to arteries, where it forms dangerous plaques.

These reduce blood flow to the heart and can rupture and break off, causing blood clots that can trigger a heart attack.

Patients with blocked arteries are currently prescribed statins or lipid-lowering drugs to reduce their levels of LDL cholesterol, but it is thought that this only slows - rather than stops - the progress of the disease.

The scientists, from the Cleveland Clinic in Ohio, who carried out this research, accept their small study has to be replicated in larger-scale work.

But they say they hope their work will lead to more studies into the potential of HDL as a target for heart disease drugs.

Encouraging

Dr Steven Nissen, the cardiologist who led the research, told the BBC: "When we carried out this research, I thought it was a long-shot, but it worked really well.

"It has opened the door to the future and the development of an entirely new treatment for heart disease."

Dr Nissen said the speed of the treatment's effect was also encouraging.

"We thought this was a chronic, progressive disease that didn't change quickly, but now we know that's not true. We can reduce the plaque burden in weeks, not months or years."

Professor Sir Charles George, Medical Director of the British Heart Foundation, told BBC News Online: "ApoA-l Milano variant is of considerable interest since some people with it seem to be protected from coronary heart disease.

"The small study shows that this modification could have positive effects in treating patients.

"There is also evidence that this treatment may produce a slight reduction in the overall amount of atheroma which could be beneficial and may have additional benefits in stabilising plaques, thereby reducing risks of a heart attack and other vascular events."

Professor George added: "More research is needed to prove the effectiveness of this treatment.

"It is also important to keep in mind that statins are proven to effectively lower cholesterol."