July 10 (HealthDay News) -- The U.S. Food and Drug Administration has approved the Eli Lilly blood-thinner Effient (prasugrel) to prevent clots in people who have an artery-clearing procedure called angioplasty.

Angioplasty involves inserting a balloon-like device into a clogged artery to open the vessel. The procedure is usually followed by insertion of a stent, a wire mesh tube designed to keep the artery open. But blood platelets tend to gather around the stent, increasing the risk of a clot that could lead to a heart attack or stroke.

In a study involving 13,608 people, the percentage of those who had subsequent non-fatal heart attacks was reduced from 9.1 percent among people who took the blood-thinning drug Plavix (clopidogrel) to 7.0 percent among those who took Effient, the FDA said in a news release.

But the agency warned that people taking Effient were at greater risk for serious, and sometimes fatal, bleeding. Labeling for the drug will include a so-called "black-box" warning of this risk, noting that people with an urgent need for surgery or those with a history of a mini-stroke called a transient ischemic attack should not use Effient.