Drug Coated Stent developed as a way to keep blood vessels open after an angioplasty. Guidelines for the testing of drug coated stents are nearing publication, a Food & Drug Administration (FDA) official said yesterday. The FDA started working on the new drug coated stent guidelines amid concerns that the medical devices are more likely than bare metal versions to raise the risk of blood clots months after the devices are implanted.
Drug coated stents were developed as a way to keep blood vessels open after an angioplasty. Currently, Johnson & Johnson, Boston Scientific Corp and Medtronic Inc make the drug-coated stents now on the market. Abbott Laboratories Inc also is expected to receive approval for a new drug-coated stent.
Stents are lattice-like devices that act like scaffolding to hold a blood vessel open
Stents are lattice-like devices that act like scaffolding to hold a blood vessel open. The drug coating is supposed to keep scar tissue from closing the artery, a common problem with the bare metal version. In 2006, the safety of drug coated stents was called into question when the Cleveland Clinic published an analysis of fourteen stent studies covering more than 6,000 patients that found those with drug coated stents were four to five times more likely to suffer from blood clots than those implanted with bare metal stents. Since then, use of the drug coated stents has dropped dramatically.
Another large study, released late last year, suggested patients who received drug coated stents were not more likely to die or suffer heart attacks than those who got bare-metal versions, fanning the debate further. A study by Swiss researchers stated that the expensive drug coated stents are not worth using in many patients; however, they can be cost-effective in a subset of heart patients who have particularly narrow vessels.
New guidelines for the testing of drug coated stents
Dr. Daniel Shultz, the FDA’s medical device head, said yesterday that new guidelines for the testing of drug coated stents would be released within days or weeks. Shultz said the new guidelines will address stent design, the polymer used to adhere a drug to stents and the drugs used, among other factors for laboratory and human testing.
Schultz said the FDA has tried to learn from that initial experience and is working with companies as they embark on newer versions. “We would like to see broader premarket trials … but probably more importantly we need to have post-market studies that are what we call large simple trials that really do look at a broad experience of all these different types of patients,” he said.