CT scan and stress test are complementary tests


DEAR DR. ROACH: Have you heard of the 64-slice test for your heart? Would you recommend it instead of a stress test? — D.F.

ANSWER: You’re asking about a CT scan of the heart. The use of multiple detectors allows the CT scan to get a very high-resolution picture of the heart very quickly. Modern 64-slice detectors can construct an entire 3-D image of the heart in five seconds under optimal conditions. The scan is excellent at detecting calcium in the arteries, which is imperfectly correlated with blockages in the arteries. However, by adding intravenous dye, blockages in the arteries can be detected with accuracy approaching that of a cardiac angiogram. Thus, for the diagnosis of coronary artery disease, a heart CT scan can provide information similar to a stress test.

However, a stress test gives information not only on anatomy, such as blockages, but on physiology as well. By measuring the amount of time someone can exercise, and the response of the heart rate to that exercise, the cardiologist can gain useful prognostic information, which is impossible to glean from an anatomic test like a CT scan or even a cardiac catheterization and angiogram. The two tests are complementary, and we often obtain both. So, it really depends on the goals of the stress test as to which is preferred.

DEAR DR. ROACH: Recently, my acupuncturist suggested that I try hyaluronic acid capsules for the arthritis in my hands, feet, back, neck and hips. I had heard of hyaluronic acid years ago and checked it out. Since it promotes cell growth, I assume it can’t differentiate from good cells or cancer cells, so I avoided trying it. Is this really safe to take? Thank you. — C.F.


ANSWER: Hyaluronic acid is indicated for use via injection, especially into the knee for arthritis symptoms, but is also used for other purposes, such as a filler in cosmetic surgery. For knee injection, it appears safe and moderately effective. It isn’t thought to work by promoting cell growth but rather by replacing synovial fluid, a fluid that acts as a kind of shock absorber, protecting the cartilage, bone and nerves of the knee.

There have been studies evaluating oral hyaluronic acid, and one from Japan in 2012 showed a very modest improvement compared with a placebo. I wouldn’t recommend oral hyaluronic acid based on the studies done so far.

There are many reports in basic cancer research on the ability of cancer cells to grow in conditions of high hyaluronic acid; however, this does NOT mean that taking oral hyaluronic acid promotes growth of cancer cells. As far as I can tell, there is no evidence that links oral hyaluronic acid to increased cancer risk.

DEAR DR. ROACH: I have breast cancer that has metastasized to my bones. I know that there have been great strides in curing cancer at the original site but there doesn’t seem to be any work done to help when it has spread. Are you aware of any? I am 87 years old. — L.L.

ANSWER: Once breast cancer — and indeed, most cancers — has spread beyond its original location (metastasized), it becomes much more difficult to cure. However, there have been significant improvements in the treatment of metastatic breast cancer. Cure might not be possible, but a good quality of life for months or years is possible (half of women with metastatic breast cancer will live longer than two years). The exact treatment depends on the pathology and receptor status of the cancer, and a plan needs to be individualized by an experienced oncologist.

Questions about breast cancer and its treatment are found in the booklet on that subject. To obtain a copy, write: Dr. Roach — No. 1101, 628 Virginia Dr., Orlando, FL 32803. Enclose a check or money order (no cash) for $4.75 U.S./$6 Can. with the recipient’s printed name and address. Please allow four weeks for delivery.

Dr. Roach regrets that he is unable to answer individual letters, but will incorporate them in the column whenever possible. Readers may email questions to ToYourGoodHealth@med.cornell.edu or request an order form of available health newsletters at 628 Virginia Dr., Orlando, FL 32803. Health newsletters may be ordered from www.rbmamall.com.