Next-generation heart stent beats older device
By Julie Steenhuysen
CHICAGO (Reuters) - A next-generation artery-opening device from Abbott Laboratories Inc worked as well or better than an older stent at keeping blood flowing through diseased arteries, U.S. researchers said on Tuesday.
Patients using Abbott's device, the Xience drug-eluting stent, had far fewer heart attacks and heart-related deaths after one year, the researchers reported in the Journal of the American Medical Association.
The device has already won the backing of a U.S. advisory panel to the Food and Drug Administration and is expected to win U.S. marketing approval in June, joining Medtronic Inc's new drug-eluting stent, Endeavor, which won U.S. approval in February.
Stents are wire mesh tubes inserted into coronary arteries that have been cleared of blockages. Drug-releasing versions help prevent vessels from reclogging.
Results of the company-funded study of 1,000 patients known as Spirit III pitted Abbott's Xience against Boston Scientific Corp's Taxus stent. Xience proved significantly better at preventing scar tissue from renarrowing treated vessels, a measure known as in-segment late loss.
It also worked as well as Taxus in reducing rates of target vessel failure, a measure of re-treatment needed either because the device did not work or because of heart attacks or death.
And it cut major adverse cardiac events -- including heart attacks and heart-related deaths -- by 42 percent after one year.
"It looks like we are entering an era where we can have some safer and more effective drug-eluting stents," said Dr. Gregg Stone of Columbia University in New York, who led the study.
Stone said the older Taxus device performed well in the study, but Xience had a performance edge by some measures, at least through the first year of follow-up.
Drug-eluting stents burst on the scene in 2003 with the promise of revolutionizing the treatment of clogged arteries by preventing the build-up of scar tissue that often sent patients back to the hospital for a repeat procedure.
Two companies, Boston Scientific and Johnson & Johnson, shared a robust $6 billion-a-year U.S. market for drug-eluting stents for several years.
Then, patients started turning up with deadly blood clots long after the stents were implanted and doctors reverted to using older, cheaper bare-metal stents.
Dr. Manesh Patel of Duke University in North Carolina, who wrote a commentary in JAMA, said the Xience results were promising, but he said doctors will likely exercise some caution over this new generation of heart devices until longer-term safety data become available.
"We've been here before with drug-eluting stents," he said in a telephone interview.
Patel said there have been concerns about the long-term side effects of drug-eluting stents, such as blood clots. "We would have the same concerns here," he said, but added, "This generation at least may be a step forward."
Stone said the study does not address the rare but worrisome clotting issue, which typically occurs after one year.
"These are only data out to one year and we certainly need to get longer-term follow up," he said in a telephone interview. Stone will present two-year follow up data from the study next month at a medical meeting in Barcelona, Spain.
(Editing by Maggie Fox and Eric Walsh)