Coated stents win qualified backing
GAITHERSBURG, Md. -- Drug-coated stents increase the risk of potentially fatal blood clots and heart attacks in some patients, but not enough to warrant limiting use of the devices, federal advisers said yesterday .
During the second day of a two-day hearing, the Food and Drug Administration advisory panel also said most higher-risk patients, such as the elderly and diabetics, should take blood thinners for at least a year after a stent implant to ward off clotting, compared with the current recommendation of three to six months. It also recommended changing the labeling on drug-coated stents to indicate the potential dangers for higher-risk patients.
The FDA estimates roughly 60 percent of stents are implanted in patients who have health conditions that had not been studied prior to the devices' approval. The agency does not have to follow the advice of its 21-member advisory panel, but typically does .
During the hearing, the panel heard conflicting testimony from researchers about when patients are at risk for clots, whether one type of drug-coated stent is safer than another, and how long blood thinners should be used.
Stents -- tiny wire-mesh tubes used to keep arteries open after they have been cleared -- have been implanted in about 6 million people worldwide. Since their US approval in 2003, drug-coated stents have become extremely popular. The devices generate more than $2 billion annually for Boston Scientific Corp., based in Natick.
The drug coating is intended to prevent scarring, which cause the arteries to narrow, but also increases the risk that blood clots will form, compared with bare metal stents. During the hearing, panel members said US studies of drug-coated stents have been incomplete and contradictory. They called for more rigorous trials.
"I'm troubled by the state of the data," said Dr. Robert Harrington , an interventional cardiologist at Duke Clinical Research Institute .
Since the blood clot risk emerged, many cardiologists have used fewer drug-coated stents. But practicing cardiologists on the panel said that even though evidence of risks gives them pause, they would still implant drug-coated stents in patients.
Dr. Donald S. Baim, Boston Scientific's chief medical officer, said the company is "gratified that the panel concurred with our belief that the benefits of drug-eluting stents far outweigh the risks."
For those with the simplest conditions to treat, Johnson & Johnson's Cypher and Boston Scientific's Taxus devices have similar blood-clot risks, more than 1 percent . But Medtronic Inc. said yesterday that Endeavor, its drug-coated heart stent sold in Europe, has half that rate . The device is not yet for sale in the United States.
Yesterday's discussion echoed what the panel said Thursday: If used in the right patients, the benefits of drug-coated stents outweigh the risks.
Dr. Daniel G. Schultz, who leads the FDA's center for devices and radiological health, said such public forums are "the best way -- maybe the only way -- to get some movement forward, if not some resolution" on health issues like stent safety.
Diedtra Henderson can be reached at dhenderson@globe.com. 
