Feb. 6, 2008 -- A tiny vacuum threaded through an artery sucks blood clots
away from the heart, improving outcomes for heart attack patients.
Blood clots in the heart arteries
cause heart attacks, angina, and other problems. The current treatment
-- balloon angioplasty with wire-mesh stents to prop open the artery -- has
enormously increased the chances of surviving a heart attack.
Now, the odds of surviving a heart attack may be even better. Instead of
using a balloon to squash the clot against the sides of the artery, a new
technique allows doctors to vacuum away the clot.
A clinical trial compared the technique -- using the commercially available
6-French Export Aspiration Catheter from Medtronic -- to balloon angioplasty.
Felix Zijlstra, MD, PhD, director of the thorax center at the University of
Groningen, Netherlands, and colleagues randomly assigned 1,071 heart attack
patients to one treatment or the other.
"We are on the brink of a new development," Zijlstra tells WebMD.
"Instead of fragmenting clot material with a balloon -- and potentially
[sending it downstream to damage the heart], it makes sense to get rid of the
debris to start with."
As in balloon angioplasty, the new technique calls for doctors to run a
guide wire into the artery and through the middle of the blood clot. But
instead of running a balloon catheter along the guide wire, doctors use an
"aspiration catheter" -- a thin vacuum -- to suck away the clot. A
balloon is then used to push open the artery, and a stent is placed to support
the opened artery.
The idea is to keep pieces of the clot -- embolisms -- from breaking loose
and blocking smaller arteries, which can kill the sections of the heart fed by
In the Zijlstra study, such blockages were seen in 17% of the patients
treated with the new technique and in 26% of those treated with traditional
balloon angioplasty. The less downstream blockage patients had, the better
Thrombus Aspiration: Treatment Wave of the Future
The technique isn't perfect. Even the highly experienced study researchers
failed to remove the clot in 27% of cases. Still, electrocardiogram results returned
to near-normal for 56.6% of patients treated with the technique, compared
with 44.2% of patients treated with balloon angioplasty.
This isn't a giant breakthrough, but it could represent a significant
improvement in the treatment of heart attack, says George W. Vetrovec MD,
chairman of the division of cardiology and director of the adult cardiac
catheterization laboratory at Virginia Commonwealth University, Richmond.
Vetrovec's editorial accompanies the Zijlstra team's report in the Feb. 7 issue
of The New England Journal of Medicine.
"What you are really trying to do here is to limit damage to the heart
muscle by preventing clots from blocking the small vessels beyond the major
obstruction," Vetrovec tells WebMD. "Every bit of heart muscle you save
will help -- and in the heart attack setting, that is very important. You just
reduce the amount of debris going downstream and therefore have better