A report published in a supplement to the July 17 American Journal of Cardiology calls for most middle-aged men and women to undergo heart scans. It was written by the Screening for Heart Attack Prevention and Education (SHAPE) task force from the Association for the Eradication of Heart Attack, a nonprofit run organization by eminent heart specialists, but some worry that although well-intentioned, the recommendations may be ahead of the science.
The SHAPE report touted the benefits of two diagnostic tests that detect fatty plaque buildup in the arteries. The first is heart scanning using a state;–of–the–art 64 slice CT scanner–o called because it takes 64 pictures of the heart with each rotation of the doughnut–shaped machine. This scanner produces much clearer images of the heart than earlier, machines which mostly measured calcium levels, and the procedure is noninvasive. A traditional X-ray of the heart is an invasive test that involves having a catheter inserted into an artery in the groin and threaded to the heart. The second test recommended is an ultrasound of the arteries in the neck.
Currently, neither of these diagnostic tests is routinely used; however, heart scans are hot news with celebrities Oprah Winfrey and "Today" show host Matt Lauer undergoing these scans–the test even made the cover of Time magazine.
The SHAPE committee proposes testing all men aged 45 to 75 and women aged 55 to 75 at risk for heart disease even if they don’t have any symptoms. The only people excluded would be those without any of the traditional risk factors for heart disease (such as high cholesterol and blood pressure).
Noninvasive diagnostic tests, such as echocardiograms and treadmill tests, are typically reserved for people who have symptoms of heart disease (such as chest pain or shortness of breath) or those at high risk. Fatty plaques build up slowly in your arteries and you may not feel any symptoms or show signs of a problem during traditional diagnostic testing until the blockage is big enough to significantly reduce blood flow. The idea behind these newer tests is to detect the plaques before they cause problems.
Expanding the use of these relatively new tests is controversial. While they can show if there is fatty plaque buildup in any of the major arteries of the heart or neck, they can’t tell whether this plaque is likely to rupture and cause a heart attack or stroke. One concern is that some people may end up undergoing unnecessary procedures such as balloon angioplasty and stenting for minor blockages that would never have developed into anything more serious. Proponents of the scans argue that actually seeing blockages in the arteries may inspire some people to follow a heart healthy lifestyle; however, studies testing this theory have had mixed results.
In addition, heart scans use higher doses of radiation than other diagnostic tests; it is estimated that one CT scan exposes you to one fifth of the yearly allowable workplace radiation exposure set by government agencies. Another issue is that the scans, which can cost from $300 to $700, may not always be covered by insurance.
Although the SHAPE task force calls the report a "guideline", the report did not come from a recognized professional organization such as the national practice guidelines issued by the American Heart Association, American College of Cardiology, or the federal government, and it was not independently adjudicated as national guidelines are.
Currently, there are no studies showing that heart scans will lower your risk of having a heart attack or dying from heart disease and it is not clear how the results of the test would affect how you are treated. In an interview with the heart.org, Diane Bild, MD, of the Division of Epidemiology and Clinical Application of the National Heart, Lung, and Blood Institute notes that widespread testing "has not been proved to reduce mortality through randomized controlled trials, which is the type of evidence we’d like to see before making public health recommendations. Right now, the research is just not there."
Source: American Journal of Cardiology 2006;98(suppl):2-15. Reprinted from Healthywomen.gov
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