Drug-Coated Stents Don't Boost Death Risk, U.S. Advisers Say
But the devices may be the cause of blood clots, FDA panel notes
THURSDAY, Dec. 7, 2006 (HealthDay News) -- Although drug-coated stents might pose a clotting risk, they do not increase the chances of heart attack or death, a U.S. Food and Drug Administration advisory panel concluded Thursday.
While the panel of 21 experts broadly dismissed the more serious risks, they split on saying the clotting danger was real in comparison with older, bare-metal stents. They agreed only that more study of the drug-coated devices, which hold open the arteries of at least 3 million Americans, is needed, the Associated Press reported.
"There may be something there. From an evidence-based perspective, I can't say definitively one way or another," said panel member Dr. Norman Kato, of the Cardiac Care Medical Group of Encino, Calif.
Another panelist, Dr. Steve Nissen of the Cleveland Clinic, said the clotting risk was real and that only its magnitude was in question. "There is pretty unequivocal evidence," he said.
The panel, convened to advise the FDA on the safety of the stents, said any concerns fail to outweigh the benefits of the devices. On Friday, the panel will tackle the issue of the off-label use of drug-coated stents, which are inserted in patients during artery-clearing surgery called angioplasty.
The FDA isn't bound to follow the recommendations of its advisory panels, but usually does.
The key issue is whether the drug-coated stents, which have become dominant tools in the field of cardiovascular surgery since their introduction three years ago, create a heightened risk of potentially fatal blood clots. An estimated 6 million people worldwide have received the devices.
During testimony Thursday, FDA representatives concluded that existing data does indicate an increased risk for blood clots with drug-eluting stents. But they also noted the studies supporting such a conclusion were small and not necessarily conclusive.
FDA medical officer Dr. Takahiro Uchida told the panel: "It is important to note FDA does not regulate the practice of medicine. However, FDA is responsible for any use of a device that raises a public health concern," the AP reported.
The drug-coated stents release medicine designed to limit the incidence of arteries reclosing after angioplasty. The problem of reclosing is more frequently seen with traditional bare metal stents. Such re-closures require repeat surgery.
But a number of recent studies have suggested that drug-coated stents, which can cost thousands of dollars each, have long-term dangers -- most specifically, the risk of clots that could cause heart attacks. According to some estimates, drug-coated stents may cause an extra 2,160 deaths in the United States each year.
Reaction to the panel's judgment was mixed.
"I certainly hope this is a preliminary report since there is more information that should be reviewed and discussed before a final report is issued and a final decision made," said Dr. Robert Michler, director of the heart center at Montefiore Medical Center/Albert Einstein College of Medicine in New York City. "There are concerns regarding thrombosis [clotting], but there is a much broader issue here. There is widespread use of these devices which may have exceeded their appropriate use, and it's those patients we're even more concerned about."
Stents are widely used to treat three-vessel disease, although the scientific backing for their use only extends to one- and two-vessel disease, Michler explained. In addition, "there has never been demonstrated a survival benefit with stents," he said. "The only survival benefit for patients has been demonstrated with bypass surgery. We have widespread off-label use of stents for multi-vessel disease and patients dying who could have benefited from bypass surgery, and then you have the additional life-threatening situation of stent thrombosis. So what we are most concerned about is the public welfare in terms of receiving adequate informed consent about the limitations of widespread use of stents, drug-eluting stents in particular."
"Essentially, this is a very precarious situation for patients to be in who may need therapy for coronary artery disease," Michler said. "It's an enormous public health issue."
"We need better information," added Dr. Kevin Schulman, a professor of medicine at Duke University School of Medicine. "This technology has been used in a lot of patients, and it's uncomfortable that we don't have more data on the outcomes of patients in real-world clinical trials and we still have fairly substantial questions on the appropriate way to use the technology."
But one expert seemed satisfied with the panel's decision.
"My opinion is that the benefits do outweigh the risks," said Dr. Michael Attubato, associate director of invasive and interventional cardiology at New York University Medical Center. "It appears that there may be a small or increased risk of late clotting. I do believe this is a major advance in technology. Unless I see other data, I believe the benefits outweigh the risks."
Thursday's testimony was designed to address two main questions: who should or should not get the devices, and what supplementary therapies are appropriate.
According to the Washington Post, hundreds of people assembled in the large meeting room in Gaithersburg, Md., including representatives from Johnson & Johnson and Boston Scientific Corp., which make the two drug-eluting stents sold in the United States. Others present included medical device makers, physicians and patient advocates.
Anti-clotting medications such as Plavix (clopidogrel) and aspirin are often prescribed after the drug-coated stents have been implanted. And two studies published this week, in the Journal of the American College of Cardiology and the Journal of the American Medical Association, linked the increased risk of clots to discontinuation of Plavix.
Schulman, who co-authored the JAMA report, said the Duke researchers found that patients who get drug-eluting stents need to stay on blood thinners much longer than currently indicated.
"Our analysis says if you don't use stents correctly, you could be hurting patients," he said. "What kind of medication people need to be on long term is a very major concern."
For more on stents, visit the American Heart Association.