WASHINGTON (AP) - Doctors got a stern warning Tuesday to properly use a popular new drug-coated heart stent that has been linked to blood clots in almost three dozen people, including five who died.
The Cypher stent is a tiny metal scaffold that props open a cleaned-out artery and, unlike other stents, emits a drug to reduce the chances the artery will clog again.
But the drug doesn't prevent a different risk posed by all stents - blood clots that form around the device and can cause a heart attack.
The Food and Drug Administration has received reports of blood clots in 34 Cypher stent recipients. Five of those patients died, although FDA doesn't know if the clots actually caused the deaths, a spokeswoman said.
In a letter to more than 1,200 cardiac centers, manufacturer Cordis Corp. called the risk very rare considering 50,000 patients have received a Cypher stent since the eagerly awaited device began selling in April.
But Cordis cautioned that some of the clots happened after doctors improperly used the Cypher by choosing stents that were too small, implanting them improperly or not giving patients appropriate anti-clotting medicine afterward.
The Food and Drug Administration echoed that warning Tuesday.
In studies where Cypher was implanted under strict conditions, it proved no more likely to cause blood clots than long-used bare-metal stents, the FDA said.
It's not yet clear if clots among Cypher patients are occurring more often today than in those studies, said FDA cardiovascular devices chief Dr. Bram Zuckerman. He said clearly some physicians are incorrectly using the Cypher and should heed the following safe-use guidelines:
-Cypher stents are only for new patients, not to replace a reclogged stent.
-Recipients must take anti-clotting drugs for three months after getting the stent - not the mere two weeks prescribed for bare-metal stents - because arteries heal slower after Cypher insertion.
-Closely match stent size to artery diameter. Demand for the Cypher greatly eclipsed supply when it debuted, and Cordis said it initially concentrated on making smaller sizes but now offers a larger size.
-Be sure the stent is fully open, touching the artery wall.
Cordis will begin an FDA-ordered registry this month to further track Cypher outcomes. Meanwhile, doctors should report any side effects to Cordis at 1-800-327-7714, or to FDA at 1-800-FDA-1088 or http://www.fda.gov/MedWatch.