CCTA screening shows potential, but more research is necessary
Coronary CT angiography (CCTA) could eventually play a role in screening for coronary artery disease long before patients develop symptoms, but widespread adoption will require larger clinical trials.
Cardiovascular Business spoke with multi-modality cardiac imaging expert Andrew Einstein, MD, PhD, about the potential of using CCTA and other modalities to reduce the burden of coronary diseases in the U.S. He is a professor of medicine in radiology and director of nuclear cardiology, cardiac CT and cardiac MRI at Columbia University Irving Medical Center/NewYork-Presbyterian Hospital, and the incoming 2027 president of the American Society of Nuclear Cardiology (ASNC).
Einstein said the potential to identify coronary atherosclerosis earlier represents an important due to the fact that coronary artery disease remains a leading cause of death in the United States and other developed countries. As more detailed CT analysis techniques become available to identify patients with very early development of coronary plaques and coronary inflammation, using CCTA as an early detection tool for better prevention efforts could deliver significant value. Coronary disease, of course, is much easier to treat in its early stages than when it is more advanced.
Unlike colon cancer or breast cancer screenings, which have established pathways for detecting disease before symptoms emerge, cardiovascular medicine has no equivalent universal screening strategy. CCTA could offer a more comprehensive assessment of coronary plaque than traditional coronary artery calcium scoring, but Einstein said its value must be established through carefully designed studies.
“We really need good clinical trials focused on the U.S. population,” he said, noting that the results of studies such as SCOT-HEART 2 in Scotland and a large trial being conducted by Cleerly could help inform the debate, although results are still a few years away.
Radiation exposure and cost-effectiveness considerations in cardiac screenings
Radiation dose is one of the major challenges to using CCTA for population-wide screening. Einstein cautioned against conducting scans in millions of adults without first ensuring that the benefits outweigh the risks, particularly if radiation exposure remains high.
Keeping radiation doses as low as reasonably achievable (ALARA) is essential, he said, especially if screening is expanded to people who do not have symptoms.
Another question that needs to be answered is whether imaging is the most effective way to prevent cardiovascular events. An alternative would be to expand preventive treatment, including the earlier use of generic statins and more aggressive lipid-lowering targets, potentially reducing the need for imaging in some populations.
Einstein said earlier cost-effectiveness work by his group suggested that broadly prescribing statins could be an effective strategy because cardiovascular risk factors do not identify every person who will experience a heart attack. Many patients experiencing a first myocardial infarction have not previously been diagnosed with established cardiovascular risk factors.
However, he is wary of placing the entire population on medication without stronger evidence. A targeted screening strategy could offer a middle ground, using CCTA at particular ages, or in patients with risk enhancers such as kidney disease, metabolic disease or other factors associated with elevated cardiovascular risk. Imaging findings could then help determine how aggressively to lower cholesterol. Many patients can reach LDL cholesterol levels below 70 mg/dL using generic statins alone or in combination with ezetimibe, while newer therapies can be considerably more expensive.
Getting more out of imaging data
Even if dedicated CCTA does not become a universal screening test, Einstein sees substantial opportunities to identify cardiovascular risk through information already captured during imaging performed for other reasons.
For example, a chest CT ordered to investigate a persistent cough may reveal coronary calcium, aortic enlargement or other findings relevant to cardiovascular health. Nuclear cardiology studies also contain information that could help identify patients at risk, including measurements of aortic size and the volume and inflammation detected from pericardial and epicardial fat.
He is also an advocate for using opportunistic screening, where incidental findings are reported and followed up on for things like calcium seen in the coronaries on non-cardiac chest CTs, or breast artery calcifications (BAC) seen on mammograms. These findings are not always reported, and even if they are, they are rarely followed up on. But newer opportunistic artificial intelligence (AI) algorithms can run in the background and report these findings and initiate automated notifications for proper cardiology followup.
Connecting imaging findings across healthcare systems
Incidental findings need be communicated to patients and their care teams and incorporated into clinical workflows, Einstein said.
He pointed to healthcare systems in countries such as Sweden and the Netherlands, where centralized imaging infrastructure can make it easier to access studies performed across different facilities. In the United States, fragmented healthcare delivery and multiple electronic health record systems than do not communicate well between each other can make follow-up care especially difficult.
Einstein said these barriers are particularly important for patients outside major academic medical centers, including those receiving care in community and rural settings. The goal should be to ensure that incidental cardiovascular findings do not go unused simply because a scan was ordered for another condition or performed at a different institution. Many experts in radiology and cardiology believe AI will likely play a much bigger role in this area in the years ahead.
Dave Fornell has covered healthcare for more than 17 years, with a focus in cardiology and radiology. Fornell is a 5-time winner of a Jesse H. Neal Award, the most prestigious editorial honors in the field of specialized journalism. The wins included best technical content, best use of social media and best COVID-19 coverage. Fornell was also a three-time Neal finalist for best range of work by a single author. He produces more than 100 editorial videos each year, most of them interviews with key opinion leaders in medicine. He also writes technical articles, covers key trends, conducts video hospital site visits, and is very involved with social media. E-mail: [email protected]