What a CT calcium score can and cannot tell you about heart health?

A CT calcium score is increasingly used to evaluate cardiovascular health, but many patients misunderstand what the test can and cannot reveal. According to neurologist Dr Sudhir Kumar, the scan is a powerful tool for assessing heart disease risk, yet its results should always be interpreted within a broader clinical context.

Sharing insights on X on June 15, Dr Kumar explained that while the test helps identify calcified plaque in the coronary arteries, a “normal” result does not automatically mean a person is free from heart disease.

What is a CT calcium score?

A CT calcium score, also known as a coronary artery calcium (CAC) score, is a quick, non-invasive computed tomography scan that measures calcium deposits within the coronary arteries.

These calcium deposits indicate the presence of atherosclerosis, a condition in which plaque builds up inside arteries. According to Dr Kumar, higher calcium scores generally reflect a greater burden of arterial plaque and a higher future risk of heart attacks and other cardiovascular events.

One of the most significant findings from the test is a CAC score of zero.

“Multiple large studies have shown that people with CAC equal to zero generally have a very low risk of heart attack over the next five to 10 years,” Dr Kumar noted.

When is the test most useful?

The neurologist said CT calcium scoring is particularly helpful for adults over 40 who do not have symptoms but fall into a borderline or intermediate cardiovascular risk category.

This may include people with:

Mildly elevated LDL cholesterol levels

A family history of premature heart disease

Uncertainty about whether statin therapy is necessary

In such cases, the test can help doctors refine risk assessments and make more personalised treatment decisions.

Dr Kumar added that CT calcium scoring may also assist in evaluating some patients experiencing chest discomfort. For individuals with a low-to-intermediate likelihood of coronary artery disease, a zero calcium score can significantly reduce the probability of major obstructive disease.

However, he stressed that symptoms should never be ignored solely because of a reassuring scan result.

Understanding the limitations

Despite its value, CT calcium scoring has important limitations that patients should understand before relying on the results.

The test detects only calcified plaque. It does not identify softer, non-calcified plaque, which is more common in younger individuals and can still lead to heart attacks.

As a result, a zero calcium score does not necessarily mean the coronary arteries are completely healthy.

“Therefore, a zero calcium score does not mean zero coronary disease,” Dr Kumar explained, adding that persistent or typical angina symptoms should never be dismissed based only on a calcium score result.

Not a replacement for comprehensive heart care

While CT calcium scoring remains one of the most effective tools for refining cardiovascular risk assessment, Dr Kumar emphasised that it should not replace a comprehensive approach to heart health.

Clinical evaluation, management of risk factors, healthy lifestyle habits and appropriate investigation of symptoms remain essential components of cardiovascular care.

Experts continue to view the test as a valuable aid in decision-making rather than a standalone measure of heart health, highlighting the importance of interpreting results alongside an individual’s overall medical profile.

Note to readers: This article is for informational purposes only and not a substitute for professional medical advice. Always seek the advice of your doctor with any questions about a medical condition.