Can Drug-Coated Stents Beat Bypass?
3-Year Survival Similar for Drug-Coated Stent and Bypass, but Still Too Early to Tell
Side Effects Compared
Cholesterol plaque-laden arteries eventually narrow -- a life-threatening
condition called atherosclerosis.
Using a catheter inserted into an artery, interventional cardiologists push
a balloon-like device into narrowed coronary arteries (the coronary arteries
supply the heart muscle with blood). They then carefully inflate the balloon to
widen the artery. After this process, called balloon angioplasty, stents may be
used to keep the artery propped open.
About a third of the time, bare-metal stents clog back up. Newer stents
carry a drug coating that prevents clogging. But drug-coated stents have their
own problems. The most serious one is that, once in a while, they cause a blood
clot to form in the opened artery. This can lead to a fatal heart attack -
sometimes years after the stent is put in.
It's a rare event. But anyone who gets a drug-coated stent has to take
powerful anticlotting drugs for at least a year. This means that bare-metal
stents are still the best choice for some patients.
"Time was, 90% of these patients got drug-coated stents. Now we're down
to about 50% to 60%. That is a big drop," Shah says. "Some estimate the
correct proportion should be 30% to 40% of stenting should be with drug-coated
stents, and the rest with bare-metal stents."
For other patients -- especially those with blocked coronary arteries very
close to the aorta (the main artery from the heart) or those with multiple
blockages in major coronary arteries -- bypass is the best choice.
And many patients will do better with no procedure at all. Cardiologists are
getting better and better at treating patients with an aggressive combination
of drugs that prevent heart disease from getting worse.
How does a patient decide?
"Medical management is just as good as stenting in patients with
chronic, stable heart disease," Shah says.
"The time where a stent is appropriate is where the heart disease
severity doesn't greatly imperil your medium-term risk of dying of coronary
artery disease," Wilson says. "This takes an honest discussion between
the doctor and the patient. The doctor says, 'I can do this, but my chance of
causing a heart attack is X.' Some patients will say to go ahead. Others will
say, 'Whoa, let's try beta-blockers and aspirin and cholesterol-lowering drugs
for awhile and see if I really need a procedure.'"