Doctors have unraveled a new way in which a widely used kind of blood pressure drug, known as an ACE inhibitor, can help prevent heart attack and strokes.

Research presented on Tuesday showed for the first time that the drugs not only reduce hypertension, or high blood pressure, but also help protect the lining of blood vessel walls.

Professor Roberto Ferrari of the University of Ferrara, Italy, presented the findings on perindopril, one of a number of drugs with the same mode of action, at the annual meeting of the European Society of Cardiology.

Perindopril, which is sold under the brand name Coversyl, is made by privately owned French firm Servier and is marketed by Solvay in the United States and by Daiichi in Japan.

Researchers had demonstrated a year ago that heart patients given perindopril in addition to aspirin and cholesterol-lowering statins had a 20-percent lower risk of serious cardiac events.

But Ferrari said this improvement could not be explained solely by the effect of lowering blood pressure.

To find out more, he and his team combined cells from the blood vessel wall of human umbilical cords with blood from patients in the earlier trial.

They discovered that the drug had clear benefits for the functioning of the endothelium, the innermost layer of cells inside blood vessels.

That is important for patients at risk of heart attack since a smooth and well-preserved endothelium is an important factor in preventing the build-up of artery-clogging plaques.

“This confirms that perindopril improves outcomes of patients with coronary artery disease in a much more fundamental way than simply by reducing blood pressure,” Ferrari said.

ACE inhibitors work by inhibiting angiotensin-converting enzyme, which plays a crucial role in the production and breakdown of various chemicals involved in blood pressure regulation.

In addition, however, scientists have long suspected the drugs can also improve blood vessel wall structure.