The news release reports on research suggesting that testing for plasma ceramides, a type of blood lipid, might enable doctors to identify individuals at higher risk for heart attacks and strokes even though they have healthy cholesterol levels and no evidence of coronary blockage. It provides a readable and reasonably straightforward account of what the researchers did and why it might be important, but there are a number of significant omissions.
First, the release should have acknowledged that this test — even if it does effectively identify individuals at increased risk of a heart attack or stroke — may not lead to treatment that actually lowers that risk. Knowing about an increased risk doesn’t mean that risk can be reduced. Many other similar risk markers have been proposed over the years and so far haven’t been found very useful for actually guiding treatment that improves outcomes.
Moreover, the research discussed in the release was being presented at a scientific meeting, meaning it has not yet gone through the peer-review process for publication in a journal. In addition, the news release provides no information about the costs of the new test, which appears to be available only through Mayo Medical Laboratories. It also does not discuss the possibility of false positive results, potentially leading to unnecessary treatment.
Cardiovascular disease, including heart attacks and strokes, kills more Americans than any other disease, including cancer. Although health experts have long advised people to try to maintain low cholesterol levels – especially for low-density lipoprotein (LDL) – research suggests that as many as half of all heart attacks occur in individuals who have normal cholesterol levels. In addition, heart attacks can occur in individuals, especially women, for whom angiograms show no blockage of the coronary arteries.
The news release provides no information about how much the blood ceramide test costs.
The primary benefit of the test is that it might enable doctors to identify people who are at higher-than-normal risk for heart attacks and strokes even though they have normal levels of cholesterol and show no evidence of heart blockages. The news release does a good job of explaining the likelihood of having a cardiac event for those with low versus high levels of blood ceramides. In particular, it reports both absolute and relative risk, noting that, among individuals with low LDL (bad cholesterol) levels, cardiovascular disease occurred in 3.7% of those with low ceramide levels but in 16.4% of those with high ceramide levels.
Presumably, there is little risk to individuals from the blood test itself. However, it’s important to note that among individuals with low LDL and the highest levels of blood ceramides, 83.6% did not experience cardiovascular disease. This raises the concern that use of the blood ceramide test might increase overtreatment, depending on what a patient’s doctor recommends if the test reveals high ceramide levels. It is not clear what, if anything, individuals can do to reduce their blood ceramide levels. While there’s certainly no harm in encouraging people to change their lifestyles to reduce their risk of heart disease and stroke, some health experts now argue that statins, often prescribed to decrease patients’ cholesterol levels, might do more harm than good for individuals at lower risk of heart disease.
The news release wasn’t clear about what this study cannot tell us, which is that we don’t know if the results of the blood test would make doctors change how they treat patients. Given that most patients are already on medication to treat their cardiac risk factors, measuring ceramide levels might not lead to any treatment and would just increase costs. Moreover, it’s not clear whether any changes in treatment would actually produce measurable benefits for patients who are at increased risk according to the test.
Another concern here is that the research discussed in the news release was being presented at a scientific conference and had not yet gone through the peer review process for journal publication. Research findings may change when a study report is published in a journal, and for this reason, journalists often are cautioned against building stories around conference reports. In this case, the association between ceramide levels and heart disease has been documented in other research. However, the news release’s contention that those with low LDL but high ceramide levels are four times as likely to have a heart attack, stroke or other cardiovascular event would still be considered a preliminary finding, given the lack of rigorous peer review.
Heart disease is a serious and common problem. However, the news release skirts the line here by stating in the second paragraph that “individuals with the highest levels of blood ceramides were found to have a 3- to 4-times greater risk of having a cardiovascular event compared with those with the lowest ceramide score, regardless of their LDL cholesterol level or the presence of a blockage in the heart’s arteries.” Five paragraphs later, it provides the absolute risk information mentioned earlier. What’s missing here are data explaining how heart disease risks for individuals with low LDL cholesterol, no blockages and high ceramide levels compare to the risks among individuals with high LDL cholesterol levels and/or evidence of heart artery blockage. Those numbers would’ve helped put the “3- to 4-times greater risk” in context.
The news release states that Mayo Clinic funded the trial and notes in the same paragraph that the ceramide test is available through Mayo Medical Laboratories, making the potential conflict of interest quite clear. It also notes that the study’s senior author is a Mayo Clinic cardiologist and chair of the “Division of Clinical Core Laboratory Services” and that Mayo Medical Laboratories collaborated with Finland-based Zora Biosciences to develop the test.
The news release doesn’t mention that over the past few years many new blood tests for refining cardiac risk have been researched. Independent expert guidelines do not endorse their use. How well ceramides compare to these blood tests will have to be determined by future studies.
The news release states that the “new test is available to health care providers worldwide through Mayo Medical Laboratories.” It is not entirely clear whether this is the only commercially available test of its kind.
The news release notes that Mayo Medical Laboratories first released this test in August 2016, and that “the present study is also the first to test its clinical utility in a U.S. population.”
However, while this test is new, many similar biomarkers for refining cardiac risk have been proposed over the years.
None of the language in the news release rises to the level of what we’d flag here.