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5. Stents: Safe as We Thought?
Before this year, there seemed no end to the popularity of drug-coated
stents. Patients even demanded that their cardiologists use them to prop open
their clogged arteries.
Now, as 2006 draws to a close, an heart
carry their own risk of fatal
Drug-coated stents are the latest thing in the evolving treatment of blocked
arteries. But the stent story shows that solving one problem creates
First, there were bypass operations. These open surgeries take a blood
vessel from another part of the body and use it to bypass blockage in a heart
Then there was balloon angioplasty. It calls for a doctor to thread a
catheter into a blocked artery. The catheter inflates a balloon that opens the
But the balloon-opened artery sometimes collapses again. So doctors used
wire-mesh tubes -- stents -- to prop the artery open.
Bare-metal stents sometimes get blocked by scar tissue. This led to the
invention of stents coated with drugs that keeps the scar tissue from
Now it's clear that drug-coated stents have their own problem. To work
properly, a lining of new blood-vessel cells have to heal over the inside of
the stent. Drug-coated stents delay this process. Blood clots can form on the
unhealed surface of the stent. This means that in rare cases,
How often does this happen? Deepak L. Bhatt, MD, associate director of The
Cleveland Clinic's heart center, tells WebMD that patients "are not
dropping in droves due to drug-coated stents."
"The absolute risk to an individual patient is less than one in
200," Bhatt says. But "with a million stents going in each year in the
U.S. and twice that number worldwide, this is not trivial."
Fortunately, a combination of two anticlotting drugs -- aspirin and
. Doctors used to wean stent
patients off these drugs after six months. Now studies suggest that patients
may have to stay on the drugs for at least a year.
But this solution creates its own problem. Patients with bleeding problems
-- or those who need surgery -- can't tolerate long-term anticlotting
New kinds of stents eventually will solve this problem. And if history is
any guide, they'll pose new challenges, too.