April 22, 2008 -- The new Xience stent beat the popular Taxus stent in a
one-year trial, but experts disagree on whether stent science is moving too
Stents prop open arteries that have been unclogged by balloon angioplasty.
Bare-metal stents tend to reclog more often than drug-coated stents. Doctors
were very quick to start using drug-coated stents, even in patients with far
more complex heart disease than the patients in whom the devices were
Recently, doctors were blindsided by the discovery that blood clots can form
at the site of drug-coated stents long after implantation. This led to
significant confusion, which is only just now settling down as doctors better
learn how to prevent these clots.
Now Xience, a new stent with a new kind of drug coating, seems safer and
more effective in a one-year clinical trial. Should the FDA approve it? Or
should history make the FDA wait until more is known?
Manesh Patel, MD, assistant professor of cardiology at Duke University,
argues for caution.
"We want a durable result with the device we use. That is the conundrum
in a rapidly moving science," Patel tells WebMD. "We have new devices
that may be safer and more effective, but we need time to see how well they
reduce long-term events."
Gregg W. Stone, MD, director of cardiovascular research and education at the
New York Presbyterian Hospital/Columbia University's Center for Interventional
Vascular Therapy, led the 1,002-patient study of the new stent.
Stone says it's already known that drug-coated stents -- doctors call them
drug-eluting stents -- work better than bare-metal stents in most cases. Yet
two-thirds of the time, he says, they are used in patients who have more
complex heart disease than the patients for whom the stents are officially
"Physicians have to use their judgment, based on what they know and on
the studies that have been done, to decide whether the use of a drug-eluting
stent is in the individual patient's best interest," Stone tells WebMD.
"I don't think this new stent is going to markedly change how doctors use
stents. It will just convert doctors who have used earlier stents to this one
because the outcomes look safer and more effective."