Stents--lattice-like metal tubes that expand inside an artery--are an effective way to keep blood vessels open after balloon angioplasty, but they may be overused in the United States, researchers report today in the New England Journal of Medicine. Stents were introduced only about four years ago, but 800,000 will be implanted in 500,000 Americans this year.
Stents work best when short segments of arteries have clogged, but some surgeons implant them over much longer stretches, according to the reports. Many physicians also are not prescribing appropriate drugs to prevent clot formation triggered by the stents. One of the studies in the journal showed that aspirin and the blood-thinning agent ticlodipine work much better than a combination of aspirin and warfarin, another thinner, or aspirin alone.