Truth vs. Myth: The Power of Zero in Heart Health

Portrait of Doctor Agrawal at Saint Francis

In most parts of life, zero is something we try to avoid. A zero on an exam can destroy your grade. A zero in your bank account usually means trouble. Even in sports, a score of zero rarely gets you very far.

But in cardiology, zero can be one of the best numbers you can receive.

When cardiologists talk about the “Power of Zero,” we are referring to a coronary artery calcium (CAC) score of zero. This simple CT scan of the heart can provide remarkable insight into a person’s risk of heart disease.

One of the central goals of preventive cardiology is to predict risk before problems occur. If we can identify patients who are likely to develop heart disease early, we can intervene with lifestyle changes or medications and prevent heart attacks and strokes before they happen.

The challenge is that we now have thousands of tests, biomarkers, and screening tools that claim to refine cardiovascular risk. Cholesterol levels, inflammatory markers, genetic tests, and imaging studies are all available.

With so many options, an important question emerges: how do we determine what truly matters?

Most physicians begin with a risk calculator. The most widely used is the ASCVD risk calculator, which estimates the likelihood of a heart attack or stroke over the next ten years based on factors such as age, cholesterol levels, blood pressure, smoking status, and diabetes. Newer tools, such as the PREVENT risk equations, have also been developed to further refine cardiovascular risk prediction.

These calculators provide a helpful overview of risk. However, they are still statistical models. They describe population risk but do not always reveal what is happening inside an individual patient’s arteries.

This is where coronary artery calcium scoring becomes particularly powerful.

What Is a Calcium Score?

A calcium score is obtained from a quick CT scan of the heart that detects calcium deposits in the coronary arteries.

The scan itself takes about 10 seconds, with a total visit time typically 10–15 minutes. It does not require intravenous contrast or medications. Radiation exposure is low—roughly comparable to one to two mammograms.

Calcium forms as plaque builds up in the coronary arteries, making it a useful marker of atherosclerosis. By measuring the amount of calcium present, we can estimate the burden of plaque and better predict the risk of future cardiovascular events.

And sometimes—ideally—the result is zero.

The Power of Zero

When a calcium score is zero, it means that no calcified plaque was detected in the coronary arteries. This finding is remarkably reassuring.

Large population studies have consistently shown that individuals with a calcium score of zero have a very low short-term risk of heart attack—typically around 0.1% to 0.5% per year, depending on age and other risk factors.

Research also suggests that a calcium score of zero provides a kind of “warranty period.” In many individuals, a score of zero offers reassurance for approximately 3 to 7 years, depending on overall risk factors, before repeat scanning may be considered.

This means one scan can guide preventive care for several years rather than requiring frequent testing.

Understanding the Limitations

Like any test, calcium scoring has limitations.

A calcium score of zero means we do not see calcified plaque, but it does not completely rule out very early or non-calcified plaque. Research suggests that about 10% of individuals with a calcium score of zero may have non-calcified plaque detectable with more advanced imaging.

This is more common in younger individuals or in patients with certain risk factors such as diabetes or a strong family history of heart disease.

For patients with conditions such as diabetes, familial hypercholesterolemia, or active smoking, physicians may still recommend preventive medications even if the calcium score is zero. These conditions carry inherent cardiovascular risk that calcium scoring alone cannot fully capture.

Who Should Consider Calcium Scoring?

Calcium scoring is most helpful for adults between ages 40 and 75 who are at intermediate risk for cardiovascular disease—roughly a 5–20% chance of heart attack or stroke over ten years—when the decision to start preventive medications is uncertain.

The test is generally not recommended for individuals who already have known coronary artery disease, such as those who have had a heart attack, coronary stents, or bypass surgery. In those cases, plaque is already known to be present and other treatment strategies guide care.

Prevention Is the Goal

At Saint Francis Heart and Vascular Institute, coronary calcium scoring is available as a screening test for $99. The goal is not simply to perform another test, but to provide patients and physicians with better information to guide preventive care.

Modern cardiac imaging can now go even further. Coronary CT angiography can evaluate plaque in greater detail, including plaque that has not yet calcified.

Saint Francis Heart and Vascular Institute actually developed the first clinical program in Oklahoma offering advanced plaque analysis, helping refine cardiovascular risk and personalize prevention strategies.

Still, the simple idea remains powerful; in most areas of life, zero is something we try to avoid. But when it comes to your heart, zero may be the best number your doctor can give you.

Dr. Neil Agrawal, MD, FACC

Director of Cardiac CT

Founder, Preventive Cardiology and Metabolic Disease Clinic

Heart & Vascular Institute, Saint Francis Health System