Cypher Coronary Stent Alert
Background: The Cypher Stent is an important device for treating coronary artery disease. It is a drug-eluting stent -- a tiny metal scaffold used to prop open a coronary artery that has been opened by balloon angioplasty and keep it open by eluting the drug sirolimus. Sirolimus reduces the chance of regrowth of normal tissue into the artery causing the artery to restenose (narrow again).
The FDA has advised physicians of "adverse events" associated with the Cypher Stent: (1) thrombosis (a blood clot) in close to 300 cases, over 60 of them fatal and (2) allergic reactions in more than 50 cases. "including some deaths."
Comments: The first reaction may be to say "Whoa, this is a dangerous device." But there are many questions that need to be answered. One is: What is the denominator here? How many Cypher Stents have been implanted? About 260,000 Cypher Stents have reportedly been distributed in the US and 180,000 abroad. Is that 60 deaths out of, let us say, 240,000 stents? That would be 1 death per 4,000 stents.
Did the blood clots occur despite the recommended routine or not? All patients should take an antiplatelet medication (a "bloodthinner") after receiving the stent. Cordis (the company that makes the stent) cautions that it is "very important that you take your medications exactly as prescribed" and "be sure not to miss any doses."
And were the proper precautions taken in regard to an allergy? Cordis cautions: "Persons allergic to 316L stainless steel, polymers (plastics) or sirolimus may suffer an allergic response to this implant. It is important to notify your physician if you have any known metal, plastic or drug allergies."
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FDA Advises Physicians of Adverse Events Associated with Cordis Cypher Coronary Stents
Oct 30, 2003 -- The Food and Drug Administration (FDA) yesterday informed physicians about adverse events associated with Cordis Corporation's Cypher Coronary Stent. FDA has received more than 290 reports of thrombosis (clotting) occurring one to 30 days after the procedure to implant the device. In more than 60 of these reports, use of the device was associated with the death of the patient; in the remainder, the device was associated with injury requiring medical or surgical intervention.
FDA has also received more than 50 reports, including some deaths, that Cordis considers to be possible hypersensitivity reactions. The symptoms include: pain, rash, respiratory alterations, hives, itching, fever, and blood pressure changes.
Hundreds of thousands of patients have been successfully treated with the Cypher stent. FDA does not have enough information to determine whether the incidents of thrombosis and hypersensitivity reaction with the Cypher stent differs from those experienced with bare metal stents.
FDA approved the Cypher stent in April 2003 for patients undergoing angioplasty procedures to open clogged coronary arteries. The stent, a cylindrical metal mesh, is designed to keep the arteries from re-clogging after the procedure. It is coated with a thin polymer containing the drug sirolimus that is slowly released into the patient and is intended to reduce the rate of re-blockage that occurs with other stents.
The cause of these adverse events has not yet been determined. FDA and Cordis are working quickly to gather as much information as possible about the circumstances surrounding these events. FDA is also working with the regulatory bodies of other countries to get more information about foreign experience with the Cypher stent.
Until FDA gets to the root of the problems, the agency is encouraging doctors to follow the instructions for use of the stent, and urging them to be vigilant for any patient symptom that may be attributed to hypersensitivity.
Patients who have received this stent should continue to follow their regularly scheduled plan for follow-up appointments with their doctor.
As a condition of approval, FDA is requiring Cordis to
conduct a 2000-patient post-approval study and continue evaluating patients from
trials to assess the long-term safety and effectiveness of the stent and to look
for rare adverse events that may result from use of the product.