Researchers have found that Viagra, commonly used to treat erectile dysfunction, may help prevent heart attacks and strokes in people who have stents keeping arteries open.

A team from Queen's University in Canada found that the drug regulates a single enzyme in cells called PDE5. The enzyme helps platelets in the blood form clots.

When clots form on stents, they can cause sudden, massive heart attacks and strokes, a news release on the study said.

The team's findings will be published on-line this week in the international journal Proceedings of the National Academy of Sciences.