Zero calcium score? Heart surgeon Dr Jeremy London explains why it does not mean zero risk of heart attacks

Heart disease risk is rarely determined by a single factor. Even if you are free from one or several known risk factors, that does not necessarily mean your overall risk is zero. From blood pressure and cholesterol levels to smoking, diabetes and the presence of arterial plaque, multiple factors can interact to shape your cardiovascular health. Understanding this bigger picture is particularly important when interpreting tests such as a CT calcium score, which captures only one aspect of heart disease risk.

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Dr Jeremy London, a board-certified cardiothoracic surgeon with 25 years of experience, is breaking down what a calcium score really reveals about your heart health – and whether a low or zero score necessarily means you have a lower risk of having a heart attack . In an Instagram video shared on September 16, the heart surgeon highlights, “Does a calcium score of zero mean you won't have a heart attack? Well, the short answer is no. And here's why.”

A CT calcium scoring scan is a quick, non-invasive imaging test that detects hardened calcium deposits in the coronary arteries, helping assess a person’s risk of heart disease. Since the test measures calcified plaque, it may seem logical to assume that a score of zero means your heart disease risk is negligible. However, a zero calcium score does not necessarily mean you are free from heart disease risk.

Dr London notes, “The goal of any screening test is to prevent future disease in patients without any symptoms at all. A calcium scoring CT scan measures the calcified or hardened plaque in the coronary arteries. Hardened plaque develops as soft plaque matures.”

According to Dr London, many heart attacks occur when unstable, soft plaque ruptures inside the arteries, rather than from calcified, hardened plaque itself. This is what makes soft plaque particularly concerning – a calcium score can detect calcified plaque, but it cannot identify soft, non-calcified plaque.

The heart surgeon explains, “60 to 75 percent of heart attacks occur from soft plaque that actually ruptures. Calcium scoring CT scan doesn't measure soft plaque. So in a 40-year-old that has a score of zero, they may have soft plaque that just hasn't hardened yet. Although the calcium score may be helpful in certain clinical situations, it should rarely change management.”

Arterial plaque, whether hardened or soft, is not the only factor that contributes to coronary artery disease. A range of other internal and external risk factors can also influence an individual’s overall risk of heart disease and should be considered when assessing cardiovascular health.

Dr London stresses, “Risk factors like smoking, diabetes, high blood pressure and ApoB should be addressed irrespective of your actual score. So no, a score of zero doesn't mean you're safe from a heart attack.”

Note to readers: This article is for informational purposes only and not a substitute for professional medical advice. It is based on user-generated content from social media.