A zero calcium score is reassuring, but it does not prevent a heart attack

A low calcium score may offer comfort, but it does not make a person immune to a heart attack. That is the warning from Dr Dmitry Yaranov, a US-based cardiologist who specialises in heart failure and transplantation.

On 13 May, he took to Instagram to explain the limitations of calcium score testing and what additional steps can be taken to assess cardiac risk more thoroughly.

What a calcium score actually measures

A calcium score is derived from a CT (computed tomography) scan that measures calcified plaque within the coronary arteries, Dr Yaranov explained.

It functions as a risk assessment tool, but it is not a comprehensive evaluation of all plaque in the vessels.

In low-risk patients, a calcium score of zero carries genuine reassurance — it points to a lower short-term risk of heart attack, a reduced likelihood of significant calcified plaque, and an encouraging overall prognosis.

However, Dr Yaranov was clear that a zero result does not mean zero plaque in the vessels, nor does it confer complete immunity from cardiac events.

The plaques that calcium scoring cannot see

Certain forms of plaque are entirely invisible to calcium score testing, the cardiologist noted. These include soft plaque, inflamed plaque, non-calcified plaque, and unstable plaque.

Crucially, each of these has the potential to cause a blood vessel to rupture — even when the calcium score reads zero.

"Some patients develop dangerous plaques before calcium develops," Dr Yaranov warned. Those at elevated risk include younger patients, smokers, diabetics, people with a strong family history of heart disease, individuals with inflammatory conditions, and anyone already experiencing cardiac symptoms.

When CT angiography is the better tool

To detect the soft plaque that a standard calcium score test cannot capture, Dr Yaranov pointed to CT angiography (CTA) as a more revealing alternative. The two tests serve distinct but complementary purposes.

The calcium score test is quick, involves low levels of radiation, requires no contrast agent, and measures calcified plaque only — making it useful for estimating long-term risk.

CTA, by contrast, uses an intravenous contrast agent, examines the coronary arteries directly, can visualise both soft and calcified plaque, and evaluates the degree of arterial narrowing and overall plaque burden.

Put simply, one asks how much calcified plaque is present; the other reveals what the arteries actually look like.

In Dr Yaranov's words: "Calcium scoring is great for prevention and risk refinement," whilst "CTA is better when symptoms, higher suspicion, or anatomy matter."

Both tools, used appropriately, serve the same ultimate goal — helping clinicians protect their patients' hearts.

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