In addition, the new stent, known as Xience V, appears to be at least as good as the standard Taxus stent at reducing deaths from heart disease, recurrent heart attacks, and the need for repeat procedures to open blocked heart arteries, says lead researcher Gregg Stone, MD, director of cardiovascular research at Columbia University Medical Center.
"For the patient, this means better long-term outcomes without recurrent heart problems," Stone tells WebMD.
The study was presented at the annual meeting of the American College of Cardiology.
Drug-Coated Stents in Most Cases
Since they were first approved for use in the U.S. in 2003, drug-coated stents have been the rage among cardiologists.
The stents are coated with a polymer that slowly releases a drug to keep scar tissue from forming and reclogging heart arteries after a balloon angioplasty procedure to open them -- a big problem with earlier, bare-metal stents.
But they’re not perfect. With drug-coated stents, reclogging is less of a problem than with bare-metal stents, but it’s still a problem.
As a result, researchers have been looking for ways to make drug-coated stents safer and more effective, Stone says.
Additionally, recent studies suggest drug-coated stents may carry a delayed risk of dangerous blood clots.
The new study, designed before the blood clot risks were well known, did not address the issue of which stent was better in that regard.
But the experimental stent has other advantages, Stone says.
Stent May Promote Faster Healing
Its very thin metal base is coated with a powerful drug called everolimus to discourage scar tissue. Everolimus is not approved for use in the U.S.
The polymer used to deliver the drug is very thin, nonadhesive, and nonsticky, so it may promote faster healing of the blood vessel walls.
And the metal tube itself is a highly malleable, cobalt-chromium blend. That makes it easier for the doctor to get it exactly where he wants it, Stone says.
The question, he tells WebMD, was whether the polymer and stent would work together.
To find out, the researchers studied 1,002 people with blockages in up to two arteries. About two-thirds got the Xience stent; the rest were implanted with the standard Taxus stent.
After implantation, participants were treated with the drug Plavix to prevent blood clots for at least six months.
After nine months, 8.1% of people who got the Taxus stent died, had a heart attack, or had artery reclogging, compared with only 4.6% of those who got the Xience stent.
The Xience stent also reduced reclogging of the treated arteries compared with the standard drug-coated stent (4.7% vs. 8.9%), Stone says.
The findings should satisfy regulatory hurdles set by the FDA for approving the device, Stone says.
In addition to Taxus, the Cypher drug-eluting stent, from Cordis Corp., a subsidiary of Johnson & Johnson, is also approved in the U.S.
Abbott, which makes Xience, funded the research. The company is expected to submit the data to the FDA by the end of the year.
Spencer B. King III, MD, head of interventional cardiology at Piedmont Hospital in Atlanta, says that if approved, Xience will offer another option for treating the more than 1 million Americans who undergo angioplasty each year.
That said, it won’t make the Taxus or Cypher stents obsolete, he says.
“All three stents are highly effective,” he tells WebMD. “It’s always good to have options.”