Calcium scans - are they worth it?
European Society of Cardiology
The findings, presented during a Hot Line session at ESC
Congress 2026, also revealed a striking difference in how consistently patients
took their medication. Those advised to use statins based on calcium buildup in
their coronary arteries were substantially more likely to follow their
treatment recommendations.
Although the results suggest that heart scans could help
doctors make more targeted treatment decisions, the trial did not establish
that the scan approach was as effective as conventional risk assessment.
Researchers say additional studies are needed to determine whether it offers a
better strategy for preventing cardiovascular disease.
Why Predicting Heart Disease Risk Remains a Challenge
Cardiovascular disease remains the world's leading cause of
illness and death. Much of this burden comes from atherosclerotic
cardiovascular disease (ASCVD), which develops when fatty deposits known as
plaque accumulate inside arteries, restricting blood flow and increasing the
risk of heart attacks and strokes. Coronary artery disease and ischemic stroke
are two major forms of this condition.
Several common factors increase the likelihood of developing
ASCVD, including smoking, diabetes, high blood pressure, and elevated
cholesterol. Doctors use these factors to estimate a person's cardiovascular
risk and determine whether preventive medications are appropriate.
Statins are among the most widely used treatments for lowering that risk. These medications reduce cholesterol levels, particularly low-density lipoprotein cholesterol, often called LDL or bad cholesterol. They also help lower the likelihood of serious cardiovascular complications.
However, identifying which patients stand to benefit from
statins remains a significant challenge. Some people who eventually experience
a heart attack do not appear to be at particularly high risk under conventional
screening methods.
"For far too many patients, the first symptom of ASCVD
is a heart attack," said Doctor Joseph B Muhlestein from the Intermountain
Medical Center, Murray, USA, the Principal Investigator of the CorCal Outcomes
trial. "Statins have been shown to be highly effective in the prevention
of ASCVD; however, there is a major gap in risk assessment, statin initiation,
and statin persistence."
According to Muhlestein, many people who suffer their first
heart attack, particularly younger adults, would not previously have been
classified as having enough cardiovascular risk to justify statin treatment.
This limitation has prompted researchers to investigate whether directly
examining the arteries might provide more useful information.
Can Heart Calcium Scans Improve Statin Decisions?
The CorCal Outcomes trial investigated two different
approaches for determining which patients should be advised to begin statin
therapy before experiencing a cardiovascular event.
The first relied on the pooled cohort equations (PCE), a
commonly used risk assessment tool that estimates cardiovascular risk using
traditional factors such as age, cholesterol levels, blood pressure, and
smoking status.
The second approach measured coronary artery calcium (CAC),
which provides a more direct indication of plaque buildup in the arteries
supplying the heart.
This measurement uses a computed tomography (CT) scan to
detect calcium deposits in the coronary arteries. Calcium can accumulate within
atherosclerotic plaque, making it a useful marker of underlying coronary artery
disease, even in people who have not developed symptoms.
Unlike traditional risk calculators, which estimate the
likelihood of future cardiovascular problems based on personal characteristics
and health measurements, calcium scans provide evidence of disease already
present in the coronary arteries.
Researchers wanted to determine whether using this
information to guide statin recommendations could improve cardiovascular
outcomes.
Nearly 5,800 Patients Put Both Methods to the Test
The trial enrolled 5,772 patients from the Canyons and
Desert regions of Intermountain Health Care in the United States. Participants
had no known history of ASCVD or diabetes and had not previously received
statin therapy.
Their average age was 64, and women accounted for 51% of the
study population.
Eligible participants were randomly assigned (1:1) to one of
two groups. One group received statin treatment guidance based on traditional
cardiovascular risk scores, while the other received recommendations based on
coronary calcium scan results.
Both patients and their physicians were informed of the
treatment recommendations generated by the study protocol. However, the final
decision about whether to start taking statins remained with the patients and
their doctors.
The researchers then tracked major cardiovascular events
(MACE; all-cause mortality, myocardial infarction, stroke, and arterial
revascularization).
This combined outcome included death from any cause, heart
attacks, strokes, and procedures to restore blood flow through narrowed or
blocked arteries.
Heart Scans Led to Far Fewer Statin Recommendations
After an average follow-up of 4.2 years, researchers found
that major cardiovascular events occurred at exactly the same observed rate in
both groups.
A total of 2.7% of patients in each group experienced one of
the events included in the study's primary outcome. The estimated relative risk
over time was also nearly identical (hazard ratio 0.99; 95% confidence interval
0.71 to 1.38; p=0.045 for noninferiority).
However, this similarity did not establish that the two
strategies were equally effective. The study failed to meet its predetermined
statistical requirement for demonstrating that the calcium scan approach was
not meaningfully worse than conventional risk assessment.
A notable difference emerged in how frequently patients were
advised to begin taking statins.
Participants evaluated using traditional risk scores
received recommendations to start statin therapy more than three times as often
as those whose decisions were guided by coronary calcium measurements.
Despite this substantial difference in treatment
recommendations, both groups experienced the same observed rate of major
cardiovascular events during the follow-up period.
A Surprising Difference in Statin Adherence
Perhaps the most intriguing finding involved whether
patients actually followed their prescribed treatment.
Among those advised to take statins, patients whose
recommendations were based on calcium scans were much more likely to adhere to
their medication regimen than those assessed using traditional cardiovascular
risk factors.
The difference was substantial (62% vs. 23%).
In other words, patients recommended statins based on
visible evidence of calcium buildup in their arteries were approximately 2.7
times as likely to follow their medication regimen.
One possible explanation is that seeing evidence of disease
in their own arteries makes patients more motivated to take preventive
medication. However, the trial did not establish why adherence differed so
dramatically between the groups.
The findings raise the possibility that coronary calcium
scans could influence not only which patients receive statin recommendations,
but also whether those patients consistently take the medications.
What the Findings Mean for Heart Disease Prevention
Despite these potentially important differences, the
researchers emphasized that the study could not establish whether calcium
scan-guided treatment provides cardiovascular protection comparable to
traditional risk assessment.
One important limitation was that fewer participants
experienced major cardiovascular events than the investigators had anticipated.
With fewer events to analyze, the trial had less statistical power to determine
whether a meaningful difference existed between the two approaches.
"The power of the study to detect a difference was
reduced by the lower-than-expected event rates and we did not demonstrate
noninferiority between the groups," said Doctor Muhlestein, who concluded:
"The study did provide important hypothesis-generating insights into the
efficiency of statin initiation and adherence when decisions are based on CAC
scoring. Taken together, our data could be used to plan an additional
well-powered randomized trial comparing CAC with current risk factor-based
algorithms."
The findings may help researchers design future trials
capable of determining whether coronary calcium scans can improve the
efficiency of statin prescribing without compromising cardiovascular
protection.
Current European recommendations already recognize a
potential role for these measurements. The 2025 Focused Update of the 2019
ESC/EAS Guidelines for the management of dyslipidemias recommends considering
increased coronary calcium scores, when available, as an additional factor in
cardiovascular risk assessment.
This guidance applies particularly to people at moderate
cardiovascular risk or those whose estimated risk falls near the threshold at
which preventive medication would normally be recommended.
For these individuals, evidence of calcium buildup may help
doctors make more informed decisions when the need for statin therapy is
uncertain.
The CorCal Outcomes findings add to the discussion by suggesting that heart scans may also influence how faithfully patients follow treatment. Whether that advantage translates into better long-term cardiovascular outcomes remains an important question for future research.