Warning Issued on Artery Stent

The US Food and Drug Administration (FDA) has announced the receipt of 47 medical device reports of stent thrombosis occurring at the time of implantation, or within a few days, of a sirolimus-eluting coronary stent called Cypher. There are also reports that five patients have died. The agency is carefully reviewing these reports to determine the exact causes and reduce the incidence of thrombosis.

The Cypher stent was approved in April 2003 by the FDA for patients undergoing angioplasty procedures to open clogged coronary arteries. Since introduction, it is estimated that more than 50,000 patients have received the stent. The marketer, Cordis Corporation (a Johnson & Johnson company; Warren, NJ, USA), has issued a letter to healthcare professionals to inform them of the rare but potential risk of thrombosis.

This letter also provides the following recommendations for the safe use of the stent. The stent size should match the diameter of the vessel as closely as possible. The stent is indicated for improving coronary luminal diameter in previously untreated vessels but not for the treatment of restenosis. Doctors should give adequate doses of medication that reduces the risk of clot formation. The stent should be fully deployed and in contact with the vessel wall.

As part of the approval for the Cypher stent, the FDA required Cordis to undertake post-approval studies that will help the agency track adverse events more accurately as well as help determine whether the thrombosis rate in current clinical experience differs from the rate seen in pre-approval studies. The results of these studies will be highly useful to regulators.