The New Heart Tests: Which Ones Should You Have?
Experts explain the pros and cons of coronary calcium scores, carotid artery ultrasound, and CT heart scans.
3. CT Heart Scans
What Is a CT Heart Scan?
During CT heart scans (also know as CT angiography), patients receive a
contrast dye through an IV. X-rays are passed through the body and are picked
up by detectors in the scanner. Special software uses the information gathered
during the scan to create 3D images of the coronary arteries on a computer
CT angiography scans give doctors a detailed look at the coronary arteries,
which supply blood to heart muscle, without cardiac catheterization.
Who Should Get CT Heart Scans?
While contrary calcium scores and carotid artery scans are used to evaluate
people without symptoms, CT angiography is typically reserved for
intermediate-risk people with symptoms such as chest pain or shortness of
breath that could be due to coronary heart disease, Villines says.
CT heart scans can also be useful if a patient is at low risk for heart
disease and has "mildly abnormal" results on an exercise stress test.
"Right now, these patients are referred for catheterization, but the CT
scan could help avoid that," he says.
Advantages of CT Heart
The technique is quick, producing pictures within five to 10 seconds,
compared with 30 to 45 minutes for cardiac catheterization, the "gold
standard" for evaluating blood vessel obstructions. It's noninvasive, with
less risk and discomfort than catheterization, which often requires sedatives
and sometimes a night in the hospital.
Disadvantages of CT Heart Scans
It fails to produce good images in people with a lot of calcium deposits in
their arteries, Bonow says. It should not be used in people with chronic kidney
disease or severely obese patients, Villines says.
There are also concerns about cancer risks. According to a new study, CT
angiography has the potential to expose patients to high doses of radiation,
and methods available to reduce radiation dose are not frequently used. A
recent study reported that the average radiation exposure from a CT angiogram
evaluation is equivalent to 600 chest X-rays.
Villines says that over the past two years, Walter Reed doctors have been
able to reduce radiation during CT angiography by 50% to 70% through the use of
radiation-sparing techniques. Patients should ask if such methods will be used
before having the procedure, he advises.
How much do CT Heart Scans cost?
The CT scan, including the doctors' fee, costs about $1,000. Medicare and
other insurers are still evaluating whether to pay for the scans.
In summary, there are several tests which can be used to determine whether
or not you have diseased arteries. The results of such tests could influence
the type of preventive treatments which are recommended. However, no test
is perfect and regardless of test results, optimizing lifestyle choices still
remains a cornerstone of heart disease prevention.
When it comes to your heart health, there are no hard and fast rules, our
experts say. Talk to your doctor if you have any concerns.