Panel hints too many get coated stents

GAITHERSBURG, Md. -- Federal advisers yesterday said that drug-coated stents, which have been implanted in millions, offer clear benefits to many patients but present higher clotting risks to others, suggesting they may be overused.

The Food and Drug Administration advisory hearing, which concludes today, could trigger sweeping changes in how drug-coated stents are used, such as limiting models linked to increased risk of clots, prolonging use of blood-thinning medications to prevent clots, or requiring more strongly worded warning labels.

Stents are tiny wire mesh tubes that keep arteries open after they have been cleared of clogging. The drug coating on newer models is intended to prevent scarring, which cause arteries to narrow, but is linked to slower healing. Drug-coated versions also increase patients' risks for suffering dangerous blood clots, but so far there is no conclusive evidence they increase heart-attack and death rates when used as the label intends, the advisory panel said.

Today's discussion will cover the public health implications of nearly 60 percent of the 5 million stents implanted in patients whose conditions do not meet the strict descriptions on the device labels.

"There's been so much hype leading to these meetings about a little time bomb being implanted," said Dr. Eric Topol , head of a new institute of genomic medicine program at Scripps Health. "There may be a late clotting problem, but it doesn't appear to be associated in heart attacks or deaths. I think we need to transmit that to patients."

For patients who more closely match those studied prior to FDA approval by stent maker Boston Scientific Corp. of Natick and its rival, Johnson & Johnson , the 21-member panel was uncertain about the magnitude of heightened blood clot risks and how long those risks endure.

In clinical trials, where patients are more likely to take blood-thinning drugs, the panel found safety concerns did not outweigh the stents' overall benefits.

"I would not only say no, I would say hell, no," said Dr. Christopher J. White , a researcher at Ochsner Clinic in New Orleans .

Some panelists worried the rampant use of stents in less-than-ideal patients could be driving a spike in dangerous blood clots.

Boston Scientific tracked stent use among 7,000 patients and found slightly higher death and blood clot rates when surgeons implanted them in people with complicated medical histories.

Dr. Donald S. Baim , Boston Scientific chief medical officer , said such off-label device uses did not expose patients to "excess risk" compared with such high-risk treatments as coronary artery bypass surgery .

But the panel's chairman, Dr. William Maisel , a researcher at Beth Israel Deaconess Medical Center, told Baim, "When we move further and further away from the clinical trials, we don't know what we're going to get" with regard to health risks.

Sharon-Lise Normand , a Harvard School of Public Health researcher, took Boston Scientific to task for using historical surgical data, not current mortality rates.

"In my gut, I feel that is wrong," Normand said.

Sidney Cohen , director of clinical research at Cordis Corp. , said real-world use of his company's drug-coated stents showed an "elevated risk" of dangerous clots, heart attacks, and death, as compared to clinical trials.

But Cohen said that was most likely because of the nature of treating high-risk patients, "and not the stents being studied."

Diedtra Henderson can be reached at dhenderson@globe.com.