London, Feb 7 (IANS): A common asthma drug has the potential to help delay development of a rare heart complication that lacks effective drug treatment, according to researchers.

Aortic aneurysm -- the dilation of the aorta -- is a serious condition that occurs when the wall of the aorta, the body's largest artery, weakens and swells.

The condition is largely symptom-free and is normally therefore not discovered until late in its development when it threatens to rupture and cause life-threatening haemorrhaging.

The findings showed that the asthma drug montelukast blocks leukotrienes -- inflammatory signal substances -- that drives inflammation and are known for their potential to cause asthma.

"Our results are exciting and open the way for a medical treatment of this serious vascular disease," said Jesper Z. Haeggstrom, Professor at the Karolinska Institutet in Sweden.

Previous studies showed high levels of particular leukotrienes in the vascular walls of patients operated on for aortic aneurysm.

In the new study, reported in the journal PNAS, the team examined whether leukotrienes could also have an effect on aortic aneurysm.

The studies on mice revealed that the treatment did indeed reduce the swelling of the aorta and cut levels of an enzyme that could break down the vascular wall and a protein involved in inflammatory processes.

"This study is particularly interesting from a therapeutic perspective since montelukast is a safe drug with very few side-effects, which means it can be taken over a long period of time," Haeggstrom explained.

The disease progresses slowly and affects some five per cent of men and one per cent of women over the age of 60.

While there are currently no drugs for preventing and treating aortic aneurysm, the researchers hope to be able to start a controlled clinical trial to test the montelukast's efficacy on patients with aortic aneurysm.