BARCELONA, Spain, Sept 5 -- The long-term safety of drug-eluting stents suddenly eclipsed all other concerns this week at the world's largest gathering of cardiologists.
Many of the more than 25,000 cardiologists meeting here are shaking their heads in disbelief at the meta-analysis data that raised serious questions about the long-term safety of the coated devices.
The two meta-analyses reported Sunday at the Europeans Society of Cardiology/World Congress of Cardiology have highlighted "the dark side of drug-eluting stents," as Robert Harrington, M.D., of Duke put it.
Action Points
- Explain to interested patients that implantation of a stent requires lifelong antiplatelet therapy with aspirin.
- Explain to interested patients that data reported this week are based on meta-analyses and registries, not randomized clinical trials, and that these studies are preliminary, not having been published in peer reviewed journals.
Dr. Harrington's "dark-side" is the finding that first generation drug-eluting stents are associated with an increased risk of late stent thrombosis, an increased cardiac mortality, an increased risk of myocardial infarction, and an increased risk of all cause mortality.
But even as every hallway buzzed with the grim potentialities, should the meta-analyses be borne out by prospective randomized studies, a new positive report emerged about the drug-eluting stents. This was a report of an investigational device showing that it was superior to one of the two already approved stents.
That device is just one of a handful of second- and third- generation drug-eluting stents wending their way through the approval process.
Weighing the darker and the brighter sides of drug eluting stents has been the focus of heated discussions here, inside and outside the sessions.
An estimated six million of the first generation drug eluting stents-Cypher, a sirolimus-eluting stent, and Taxus, which elutes paclitaxel-have been implanted.
The meta-analyses reported here found that Cypher had significant risks compared with bare metal stents, while Taxus had a small, non-significant increased risk compared with bare metal stents.
The risk of thrombosis may increase when dual antiplatelet therapy is stopped. Current guidelines recommend that all stent patients take an aspirin a day for life. In addition patients who receive Cypher stents should take both aspirin and Plavix (clopidogrel) for three months, while patients treated with Taxus stents should take the drugs for a minimum of six months.
The guidelines also recommend that patients who have no excess bleeding risk should take both drugs for a year.
After that, it's anybody's guess, said Elliott M. Antman, M.D., a professor of medicine at Harvard Medical School.
He pointed out that bleeding risk increased with age, but at the same time "there are a number of other indications for [Plavix]."
One way to justify continuing Plavix would be to evaluate the patient for "disease in other arterial beds, such as peripheral arterial disease, for which Plavix is recommended," Dr. Antman said.
Other physicians said it may be necessary to evaluate changing the dual antiplatelet recommendation.
"Plavix for life? It could come to that," said Steven Nissen, M.D., chairman of cardiology at Cleveland Clinic and president of the American College of Cardiology. But Dr. Nissen cautioned against any snap judgments until "there is solid evidence of increased risk-evidence from a well-designed, large, randomized trial."
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Sidney Smith, Jr. M.D. University of North Carolina |
Sidney Smith, Jr., M.D., a professor of cardiology at the University of North Carolina in Chapel Hill, also sounded a note of caution. He pointed out, for example, that "we don't even know if these excess events occurred in the stented artery."
While waiting for more evidence, Dr. Antman advised physicians to make sure that patients have completed a year of dual antiplatelet therapy. "If patients stopped the regimen short of a year, they should be restarted until they have accumulated 12 months of dual antiplatelet therapy."
Patients sometimes stop antiplatelet therapy on the advice of another physician. For example patients undergoing surgery may be told to stop aspirin or Plavix. Likewise patients who complain about bruising are often advised to stop aspirin -- and many times that advice comes from a primary care physician, said Raymond Gibbons, M.D., a Mayo Clinic cardiologist and president of the American Heart Association.
Drs. Gibbons and Antman said that both patients and physicians should only stop an antiplatelet drug after consulting the patient's cardiologist.
"I tell patients don't stop any drug without first talking to me," said Dr. Antman.