New scrutiny for stents
The Food and Drug Administration meets this week to study reports some cardiac devices cause clottingDec 4, 2006 | Newsday
The tiny lattice-like props that keep arteries open and blood flowing freely come under scrutiny this week when the U.S. Food and Drug Administration holds a two-day meeting on drug-coated stents.
Also known as drug-eluting stents, the devices arrived on the medical scene with great fanfare in 2003 when they were approved by the FDA.
Now, a spotlight has been trained on coated stents because after three years on the market, doctors are finding that some of the 6 million patients with them worldwide are developing potentially dangerous clots. The FDA will determine whether the stents require further study or added warnings.
Word that clots were associated with drug-eluting stents first surfaced in September at an international meeting of cardiologists in Barcelona, Spain. There, researchers presented data showing that clots were occurring as late as three years after coated stents were put in place.
Burt Cohen, director of Angioplasty.org, a consumer advocacy group, said his Web site, which maintains a blog and posts reports about coated stents, has received 90,000 hits a day since September.
Doctors are noticing that patients are paying attention to the news. "It has changed my practice slightly," said Dr. Stephen Green, associate director of the catheterization laboratory at North Shore University Hospital in Manhasset. "But I talk to my patients, and for most of them the drug-coated stent is the stent of choice.
Green, citing federal statistics, estimates that only three to four people per every 1,000 receiving a coated stent will experience late-stage clotting.
When risks and benefits between drug-coated stents and the bare metal variety are weighed, Green said, the drug-coated devices still come out looking much better.
There are two brands of coated stents on the market. One is called the Cypher stent, manufactured by Cordis, a division of Johnson & Johnson. The other, the Taxus stent, is made by Boston Scientific Corp.
After placement of the Cypher stent, patients must take baby aspirin and the anti-clotting drug Plavix for three months; the Taxus stent requires six months of the medications.
"I don't think they'll go so far as a black box warning because there has not been a serious increase in deaths," said Dr. Kirk Garratt, clinical director of cardiovascular research at Lenox Hill Hospital in Manhattan. A black box warning is the highest level of FDA warning.
Dr. David Brown, chief of cardiovascular medicine at Stony Brook University Hospital, thinks a black box warning is out of the question. "My guess is that a couple of things will come out of the meeting: One would be to take Plavix for a longer period than currently recommended."
Dr. Robert Califf, a heart specialist at Duke University, who will provide one of the many scientific papers to be presented at the FDA meeting on Thursday and Friday, said the devices were implanted faster than scientists could collect data.
"As is frequently seen with new cardiac devices, a rapid increase in clinical adoption quickly outstripped what is known about the device from limited clinical trials," he said in a statement Friday.