WASHINGTON - Patients implanted with drug-coated stents to hold open their choked arteries face a small but significant risk of blood clots, health officials said Tuesday, and a new study recommended they take clot-busting medications indefinitely.
Growing concern about the long-term safety of drug-coated stents comes to a head this week, when the Food and Drug Administration convenes a two-day meeting to discuss clotting risks associated with the devices.
In documents released Tuesday, the FDA said it is unknown whether there is an increased risk of death or heart attack in patients fitted with the so-called drug-eluting stents. However, those patients do face an increased risk of blood clots a year or more after surgery compared with those fitted with bare-metal stents, the agency said in citing recent studies.
The FDA is seeking advice on a wide range of questions on the popular stents, including whether to update their labels with new warnings, identify patients for whom they aren't appropriate and perhaps change federal recommendations on how long people should take blood thinners like Plavix and aspirin following stent surgery.
The agency also wants advice on what research is needed, both on the drug-coated stents already on the market and others it has yet to consider approving.
Coated with drugs
The miniature lattice-shaped tubes are coated with drugs that slowly dissolve - or elute - into the bloodstream to prevent regrowth of tissue that can clog arteries anew. Boston Scientific Corp. and Johnson & Johnson are the only two companies approved to sell the drug-coated versions.
Labels on those stents recommend patients take baby aspirin and Plavix for either three or six months, depending on the manufacturer, following surgery. Many patients remain on the drugs longer.
Multiple studies have suggested the risk of blood clots, heart attack and death rises in patients who stop taking those drugs early. The FDA staff said it is unknown how long patients should remain on the drugs to prevent life-threatening clots from forming.
In the new study, researchers found that patients who quit taking Plavix even six or 12 months after receiving a drug-coated stent faced more than twice the risk of premature heart attack or death than did those patients who remained on the pricey drug. Plavix, also known as clopidogrel, can cost $1,400 a year.
"The bottom line from our paper, for doctors and patients, is these results tilt the balance to the fact you should stay on clopidogrel if you have a drug-eluting stent indefinitely until further data tell us how long you should be on it," said Dr. Robert Califf, a Duke University cardiologist.
On the Web
Journal of the American Medical Association: jama.ama-assn.org
Food and Drug Administration: www.fda.gov