Coronary Calcium Score vs Coronary CTA

"Your calcium score is zero."

Most people hear those words and think they are "in the clear."

But what if I told you that a patient could have a calcium score of zero and still have severe coronary artery disease?

In fact, the image above demonstrates exactly that.

This patient had:

▪ CAC Score = 0

▪ Significant non-calcified plaque burden

▪ Severe coronary artery disease

▪ Physiologically significant disease identified by FFRct

There was no detectable calcium.

Yet there was clearly detectable atherosclerosis.

As a preventive cardiologist, this is one of the most important misconceptions I encounter.

A calcium score is an excellent test.

But it is not a complete plaque test.

What Does a Coronary Calcium Score Actually Measure?

Coronary artery calcium (CAC) scoring measures calcified plaque within the coronary arteries.

The higher the calcium score, the higher the burden of calcified atherosclerosis and the higher the future cardiovascular risk.

A calcium score of zero is generally reassuring and is associated with lower short-term cardiovascular risk.

However, it is important to understand what CAC does—and does not—measure.

A calcium score identifies calcified plaque.

It does not identify:

▪ Soft plaque

▪ Non-calcified plaque

▪ Low-attenuation plaque

▪ Total plaque burden

▪ High-risk plaque features

▪ Coronary artery narrowing

Simply put:

CAC tells us whether plaque has calcified.

It does not tell us whether plaque exists.

The Evidence: Zero Calcium Does Not Always Mean Zero Plaque

This is not merely a theoretical concern.

Large contemporary studies have demonstrated that coronary plaque may exist even when CAC equals zero.

The SCAPIS study, which evaluated more than 30,000 middle-aged adults using Coronary CTA, found that approximately 5.5% of individuals with CAC = 0 still had coronary atherosclerosis.

The Miami Heart Study demonstrated that approximately 16% of asymptomatic adults with CAC = 0 had coronary plaque detected on Coronary CTA.

The key takeaway?

Plaque often begins as soft, non-calcified plaque long before calcium develops.

By the time calcium becomes visible, atherosclerosis may have already been present for years.

Why Coronary CTA With Plaque Analysis Is Different

Coronary CTA allows us to directly visualize the artery wall and characterize plaque.

Beyond calcium, Coronary CTA can identify:

▪ Non-calcified plaque

▪ Mixed plaque

▪ Total plaque burden

▪ Plaque location

▪ Degree of stenosis

▪ High-risk plaque features

▪ Functional significance with FFRct

Instead of asking:

"Has plaque calcified?"

Coronary CTA asks:

"Is coronary artery disease present?"

Those are fundamentally different questions.

Why Soft Plaque Matters

Not all plaque carries the same risk.

One of the most important findings from the SCOT-HEART trial was that low-attenuation plaque burden was among the strongest predictors of future myocardial infarction.

These lipid-rich plaques may be biologically active and more vulnerable to rupture.

In many cases, these high-risk plaques develop years before substantial calcification appears.

In other words:

The plaque most likely to cause a future heart attack may not be visible on a calcium score.

The Future of Preventive Cardiology

Historically, cardiology focused on detecting disease after symptoms appeared.

Modern preventive cardiology focuses on identifying disease before symptoms develop.

The goal is not simply finding blockages.

The goal is understanding the biology of atherosclerosis early enough to change its trajectory.

This is especially important for individuals with:

▪ Family history of premature heart disease

▪ Elevated Lipoprotein(a)

▪ Diabetes or prediabetes

▪ South Asian ancestry

▪ Metabolic syndrome

▪ Executive and high-performance lifestyles

For these individuals, Coronary CTA with plaque analysis may provide actionable information that a calcium score alone cannot.

My Clinical Perspective

I still use coronary calcium scoring regularly.

It remains one of the most valuable tools in preventive cardiology.

However, when the goal is precision cardiovascular prevention, Coronary CTA with advanced plaque analysis often provides a far more complete picture of coronary health.

The future of prevention is moving beyond asking:

"Is calcium present?"

The future is asking:

▪ How much plaque exists?

▪ What type of plaque exists?

▪ Is it progressing?

▪ Is it high-risk?

Because the earlier we identify atherosclerosis, the greater our opportunity to prevent the first heart attack rather than reacting after it occurs.

At Pulse Perfect, our philosophy is simple: