High-Tech Scans Spot Heart Blockages
Sophisticated CT Scans May Help Avoid Unnecessary Procedures
WebMD News Archive
Nov. 5, 2007 (Orlando, Fla.) -- High-tech heart scans may help some people
to avoid invasive, and sometimes unnecessary, procedures to check for blockages
in the coronary arteries, researchers say.
In a new study, the sophisticated 64-slice computed tomography coronary
angiography scan proved nearly as accurate as standard cardiac catheterization
at spotting blocked coronary arteries.
The scans won't replace cardiac catheterization, also known as coronary
angiography, but they can help doctors rule out people who can skip the more
invasive procedure, says researcher Julie Miller, MD, assistant professor of
medicine at Johns Hopkins Hospital in Baltimore.
Studies suggest that as many as one in four of the 1.3 million cardiac
catheterization procedures performed each year in the U.S. may be unnecessary,
CT Heart Scans Quick, Noninvasive
Early detection of blockages is critical to preempting a
heart attack, allowing time for drug therapy, angioplasty, or
heart bypass surgery to be used to keep arteries open.
Cardiac catheterization is the gold standard for evaluating blood vessel
obstructions. In the procedure, contrast material -- a substance that makes it
easier to see in an X-ray -- is injected through the catheter. Then an X-ray is
taken of the area to look for blockages.
While it sounds like a mouthful, the 64-slice computed tomography coronary
angiography scan is rapidly joining the health lexicon. It's a type of
CT scan that gives doctors a detailed look at the coronary arteries, which
supply blood to heart muscle.
The technique is quick, producing pictures within five to 10 seconds,
compared with 30 to 45 minutes for catheterization, Miller says. It's
noninvasive, with potentially less risk and discomfort than catheterization,
which often requires sedatives and sometimes a night in the hospital.
The potential complications of catheterization, while extremely rare,
include infection, heart attack, and
stroke, Miller says.
CT Heart Scans Relatively Accurate
The study involved 291 men and women over age 40 who were scheduled to have
catheterization to check for blocked arteries. Each underwent a 64-CT scan
prior to catheterization.
The findings were presented at the American Heart Association's Scientific
After a year, Miller says that in spotting blockages, the results of the
heart scans matched up with the catheterization results 90% percent of the
However, the CT scans were not very good at locating exactly which vessel
was blocked, the study showed.