Newest Coated Stent Does Well in Real-World Trial
Safe and effective in an 'all-comer population,' researchers say
WEDNESDAY, June 17, 2009 (HealthDay News) -- The newest drug-coated stent has performed well in a real-life trial, Dutch cardiologists report.
The Xience stent -- a flexible metal-mesh tube coated with the drug everolimus -- is inserted to keep blood flowing after artery-opening procedures such as angioplasty, and is already in widespread use. It was approved by the U.S. Food and Drug Administration last July, on the basis of good results in controlled trials.
But those trials included only people with simple artery blockages and the effectiveness of the new stent in "complex, unselected patients treated in daily practice still remains unknown and cannot be extrapolated from these randomized controlled trials," said cardiologists at Erasmus Medical Center in Rotterdam in their report, which was released online June 17 in advance of publication in the Journal of the American College of Cardiology. "We therefore sought to evaluate the impact of this second-generation drug-eluting stent on the clinical outcomes in consecutive patients treated in a real-life, all-comer population."
The trial compared the outcomes of 649 people given Xience stents with individuals who previously had stents implanted -- 450 with bare-metal stents, 508 with stents coated with the drug sirolimus and 576 with stents coated with the drug paclitaxel. The data include people with multiple artery blockages and some treated after heart attacks.
In the cautious phrasing of the Rotterdam group, "this study suggests that the use of everolimus-eluting stents in an unselected population may be as safe as and more effective than bare-metal stents, may be as safe and effective as sirolimus-eluting stents, may be as safe as paclitaxel-eluting stents, and may be more effective than paclitaxel-eluting stents."
Specifically, in a six-month follow-up period, the incidence of death, heart attack and stenosis (new blockage of the artery) was lower for the Xience group than for those with bare-metal stents and slightly better than those with first-generation drug-eluting stents.
This is good news, said Dr. Gregg W. Stone, an interventional cardiologist who is a professor of medicine at Columbia University and who took part in the controlled trials that led to FDA approval of Xience.
"This more real-world experience is reassuring," Stone said. But additional studies are needed because "the patient size in this trial was small, and it is more difficult to draw conclusions from non-randomized trials," Stone explained.
Nevertheless, the American cardiology community appears to have drawn its own conclusions already, Stone said. Drug-coated stents now are used in about 75 percent of cases, and the Xience stent is used in "50 to 60 percent of that 75 percent," he said.
Everolimus is a more potent drug than those used in the first-generation coated stents and also is contained in a thin, inert polymer that is less likely to cause inflammation, Stone said. The Xience stent itself is also thinner than the previous devices, he added.
"This is a good step forward on evaluating the next generation of drug-eluting stents," said Dr. Manesh Patel, director of the catheterization research laboratory at Duke University.
"The data I see from the [new study] is reassuring," Patel said. "If you are a patient who is being evaluated and a stent is being considered for your coronary, this stent looks safe for at least six months."
Longer follow-up data on more recipients is needed, he noted. Abbott Vascular, which markets the Xience V stent, is sponsoring a data bank that already has information on 5,000 recipients, Patel said.
Stent research and development continues, Stone stated. A stent with a bioabsorbable polymer that disappears is being tested, and further down the road is a stent that itself would dissolve over time, he said.
The why and how of stents are explained by the U.S. National Library of Medicine.