In an early look at SCOT-HEART 2, CCTA led more primary-prevention patients to make changes to reduce their risk of CVD.

Use of coronary CT angiography (CCTA) is associated with greater early adherence to lifestyle recommendations and acceptance of preventive medical therapy when compared with risk scoring alone in adults without cardiovascular disease, according to a substudy of the ongoing SCOT-HEART 2 trial.

The findings further the notion that CCTA results motivate patients and physicians to make positive changes, but more research is needed to show an effect on hard outcomes, say researchers.

“Telling somebody that their risk over X number of years is 10% or 15% . . . feels remote, like an abstract result, and I think the motivation for change in that situation can be quite low,” lead author Michael McDermott, MBChB (University of Edinburgh, Scotland), told TCTMD. “Whereas if you have a scan and you see that you’ve got atheroma . . . at that point, the majority of patients are more prepared to accept preventative therapy and, in our study, more prepared to make lifestyle changes which we observed out to 6 months.”

Jonathon Leipsic, MD (University of British Columbia/St. Paul’s Hospital, Canada), who was not involved in the study, agreed.

“There’s relatively well accepted information that CT-informed medical management leads to better adherence,” he told TCTMD. “This just shows this in an asymptomatic population and I think highlights mechanistically why we would potentially see an improvement in outcomes because of the titration of medical therapy based on the presence or absence of disease. I think that’s quite important.”

The SCOT-HEART 2 study, with plans to enroll approximately 6,000 patients at risk for cardiovascular disease, is designed to determine whether screening with CCTA is more effective than risk scoring to not only guide the use of preventative therapies, but also reduce the risk of myocardial infarction. The study follows SCOT-HEART, a landmark trial that showed use of CCTA in patients with chest pain reduced the risk of death and myocardial infarction over 5 years when compared with standard care.

CCTA in Primary Prevention

For the analysis, published online last week in JAMA Cardiology, McDermott and colleagues included 400 participants without known CVD (median age 62 years; 49.5% female) enrolled in SCOT-HEART 2 who were randomized to cardiovascular risk scoring (n = 195) or CCTA (n = 205) between September 2020 and January 2024. Median 10-year cardiovascular risk was estimated to be 15% in the risk score group and 13% in the CCTA arm. Among those who received CCTA, 49% had normal coronary arteries, 42% had nonobstructive disease, and 9% had obstructive disease.

By 6 months, those assigned to CCTA were more likely than those in the CV risk score group to comply with the National Institute for Health and Care Excellence (NICE) recommendations for diet, BMI, smoking, and physical exercise (primary endpoint; 17% vs 6%; OR 3.42; 95% CI 1.63-6.94). This was driven by significantly higher rates of achieving a healthy BMI and complying with dietary advice.

Additionally, less preventive therapy was offered after CCTA (51% vs 75%), but patients more readily accepted recommendations for treatment (77% vs 46%; P < 0.001 for both). This resulted in a similar use of lipid-lowering therapy (35% vs 44%; P = 0.08), but antiplatelet therapy was more often used following CCTA (40% vs 0.5%; P < 0.001).

Management guided by CCTA also translated to improvements in risk factors like weight, BMI, waist circumference, diastolic BP, mean arterial pressure, total cholesterol, LDL cholesterol, and step count, with greater strides made among those with CT-defined coronary atheroma.

Lastly, by 6 months, the 10-year cardiovascular risk score dropped from 13% to 11% in the CCTA group (P < 0.001), but no such change was observed in the risk score arm.

Until we’ve got randomized clinical trial data, I would probably be a little bit cautious of making firm recommendations on when and where we should use CT angiography. Michael McDermott

“A picture paints a thousand words,” McDermott said, explaining the likely reasoning behind their findings and how they are likely generalizable to populations outside of Scotland. “The presence of coronary artery disease on CT angiography transcends all language barriers. It allows patients to comprehend their own personalized and individual risk and not the population’s risk.”

He was careful to point out that this is not an all-comers study, though, and as such, cannot lend support to a population screening program just yet.

“Ultimately, we need to see what the main SCOT-HEART 2 study finds,” McDermott said. “We need to understand where the biggest risk reduction is, if we do see a risk reduction in coronary artery events. . . . Until we’ve got randomized clinical trial data, I would probably be a little bit cautious of making firm recommendations on when and where we should use CT angiography.”

For Leipsic, the analysis doesn’t address one critical question: should CT angiograms be performed in patients who are well without symptoms? It also doesn’t give insight into how well CCTA performs as a motivational tool compared to calcium scoring, “which is being used increasingly in that population,” Leipsic said. Nonetheless, when the test results are available, these insights are useful for patients and physicians.

“This is just a further reminder that the richness of CT helps inform medical management, helps empower the conversation and empower the patient, and drives greater adherence and willingness to adopt medical therapy,” he said.

In an accompanying editorial, Pamela S. Douglas, MD, and Neha J. Pagidipati, MD (both Duke University, Durham, NC), encourage physicians to stay the course, while potentially keeping CCTA in mind.

“In the end, we can continue to do what we have always done: provide preventive recommendations based on calculated risk scores,” they write. “But if most patients and their clinicians are not sufficiently motivated by these scores to make lifestyle changes or prescribe preventive therapies, what is the point?” The study, they add, provides “compelling data that CCTA, and screening for subclinical atherosclerosis in general, may help us cross the last mile to effectively prevent ASCVD.”