Is it possible that medicine can detect silent heart disease and save lives with technology as reliable, safe—and apparently cheap–as the ultrafast CT calcium test described in this broadcast? It is a problem that has stumped researchers for a very long time.
The broadcast strikes several emotional chords in quick succession—the call to thwart America’s “ number one killer”; the “big headline” from a medical meeting announcing a “wake-up call” that we all “need”; the patient whose doctor said he was fine but was wrong—and the rosy dose of “minimal radiation” that just might have “saved his life”; the other patient who now has “peace of mind” because her test gave her a clean bill of health.
But the broadcast has little enthusiasm for thorny details of this test, also known as electron beam CT or EBCT:
– Evidence: The broadcast mentions none, randomized or otherwise.
– Sources: The broadcast’s scientific credibility rests on anecdotal reports of two patients and one physician-correspondent. An “n” of 2 is bad science. There is vague mention of a gathering of eminent cardiologists, but none appears.
– Harms: False-positives with this technology are legion, and hinting otherwise (“so this could be the key”) is misleading. The tests lead to additional legions of invasive and potentially harmful (and expensive) tests and procedures. False negatives are few, but they merit mention nonetheless.
– Benefits: The broadcast does not provide a quantitative estimate of potential benefits—a major omission. According to the American Heart Association, “No study has definitively demonstrated that screening with EBCT improves outcomes by reducing mortality or morbidity from [coronary artery disease].” The broadcast suggests that the test could help people with just one risk factor for heart disease. (“They need to hear about this.”) This contrasts with recommendations from the American Heart Association, which say that testing in people at low risk (or very high risk) is futile.
– Disease mongering. The broadcast teaches people to fear calcium in their arteries. Although there is good evidence showing an association between calcium scores and cardiovascular problems, the broadcast fails to point out that the test hasn’t been proven to reduce death or heart attacks.
– Treatment Options: the broadcast mentions none. The AHA statement points out that the ultrafast CT scan is “one of many contenders in a crowded field of CAD [coronary artery disease] risk-assessment tools.”
The broadcast does not mention the cost of this technology. “No study has demonstrated that EBCT reduces healthcare costs,” according to the American Heart Association.
The broadcast does not provide a quantitative estimate of the benefits. Doing so is challenging. Research suggests that high calcium scores are associated with increased risk of heart attacks. But “No study has definitively demonstrated that screening with EBCT [electron beam or “ultrafast” CT] improves outcomes by reducing mortality or morbidity from [coronary artery disease],” according to the American Heart Association. (Circulation. 2006;114(16):1761-91)
Moreover, the broadcast suggests that even people with one risk factor could benefit from this test. (“They need to hear about this.”) This contrasts with recommendations from the American Heart Association, which does not recommend testing in people at low risk (or very high risk). They say that people considering a calcium test should go first to the Framingham Risk Calculator (FRS). If their 10-year risk is >10%, research shows calcium scanning is futile. (JAMA 2004;291:210-15.)
"Unselected screening is of limited clinical value in patients who are at low risk for CHD events," acording to an AHA expert consensus statement. "The accumulating evidence suggests that asymptomatic individuals with an intermediate FRS may be reasonable candidates for [coronary heart disease] testing using [coronary artery calcium scoring] as a potential means of modifying risk prediction and altering therapy." (Circulation 2007;115;402-426)
False-positives with this technology are legion, and hinting otherwise (“so this could be the key”) is misleading. False-positives lead to additional legions of invasive and potentially harmful (and expensive) tests and procedures. False negatives are few, but they merit mention nonetheless. Tests “dictate downstream testing, treatments, and costs,” notes the AHA statement.
An AHA Science Advisory on ionizing radiation in cardiac imaging advises against routine screening. "Routine surveillance radionuclide stress tests or cardiac CTs in asymptomatic patients at low risk for ischemic heart disease are not recommended."
The expert panel notes that coronary CT scans increases by a small amount (0.05%) the likelihood that a person will die of a cancer associated with the radiation. "This 0.05% increase in risk is added to the 21% background risk for the US population." The panel says that clinicians should attempt to use "other options for answering the clinical question at hand by means that do not use ionizing radiation or choosing the type of study that exposes the patient to the lowest amount of radiation."
Young women are particularly vulnerable to radiation exposure because it increases their risk for future breast cancer.
The broadcast does not describe the quality of evidence to support the use of ultrafast CT scans. (See also “Quantification of Benefits” below.)
The broadcast teaches people to fear calcium in their arteries. Although there is good evidence that shows an association between calcium scores and cardiovascular problems, the broadcast fails to point out that the test hasn’t been proven to reduce death or heart attacks from heart disease. (See also “Quantification of Benefits” below.)
The broadcast relies on anecdotal reports of two patients and one physician-correspondent. An “n” of 2 is bad science and inadequate reporting.
The broadcast mentions none. But the ultrafast CT scan is just “one of may contenders in a crowded field of CAD [coronary artery disease] risk-assessment tools,” according to the AHA. Alternative tests include the electrocardiographic (ECG) exercise or stress test, which does not require radiation exposure.
The broadcast does not mention the availability of ultrafast CT scans, a test used to measure the amount of calcium in arteries. These tests are also known as electron beam CT or EBCT.
“This is a new test, well not, not new in the world, but new to a lot of us,” Dr. Marie Savard opens the broadcast. The test has been around a while. The network’s Dr. Tim Johnson did a piece on ultrafast CT scans for 20/20 in Jan, 2002.
The broadcast does not appear to rely solely or largely on a news release.
Systematic, Criteria-Driven
Monday at #ADA2021, an infectious disease epidemiologist, a journalist, and a researcher shared perspectives on communication of risk in the era of COVID-19: http://ow.ly/ROfR30rMeE7 @AstleyCM @garyschwitzer @berthahidalgo @ADA_DiabetesPro
Shoutouts to @susan_bewley @drkevinknopf @MichaelBaum11 in this call for more than fawning coverage from press releases for these kinds of stories.
Also, linked history inside goes back 5 years just on Grail apparently trying to become Holy Grail. https://twitter.com/garyschwitzer/status/1408849696416841731
Comments
Please note, comments are no longer published through this website. All previously made comments are still archived and available for viewing through select posts.
Our Comments Policy
But before leaving a comment, please review these notes about our policy.
You are responsible for any comments you leave on this site.
This site is primarily a forum for discussion about the quality (or lack thereof) in journalism or other media messages (advertising, marketing, public relations, medical journals, etc.) It is not intended to be a forum for definitive discussions about medicine or science.
We will delete comments that include personal attacks, unfounded allegations, unverified claims, product pitches, profanity or any from anyone who does not list a full name and a functioning email address. We will also end any thread of repetitive comments. We don”t give medical advice so we won”t respond to questions asking for it.
We don”t have sufficient staffing to contact each commenter who left such a message. If you have a question about why your comment was edited or removed, you can email us at feedback@healthnewsreview.org.
There has been a recent burst of attention to troubles with many comments left on science and science news/communication websites. Read “Online science comments: trolls, trash and treasure.”
The authors of the Retraction Watch comments policy urge commenters:
We”re also concerned about anonymous comments. We ask that all commenters leave their full name and provide an actual email address in case we feel we need to contact them. We may delete any comment left by someone who does not leave their name and a legitimate email address.
And, as noted, product pitches of any sort – pushing treatments, tests, products, procedures, physicians, medical centers, books, websites – are likely to be deleted. We don”t accept advertising on this site and are not going to give it away free.
The ability to leave comments expires after a certain period of time. So you may find that you’re unable to leave a comment on an article that is more than a few months old.
You might also like