Should Seniors Get a CAC Scan? The Heart Test That Can Reveal What Your LDL Level Can’t

You probably know your LDL cholesterol number.

Maybe your doctor tells you it’s 70.

Or 90.

Or 120.

You may even know whether it’s considered “good” or “high.”

But here’s an interesting question:

Does your LDL number tell you how much plaque is actually in your coronary arteries?

Not necessarily.

That’s where a CAC scan comes in.

What is a CAC scan?

CAC stands for coronary artery calcium.

It’s a quick CT scan that looks for calcium deposits in the walls of the arteries supplying your heart.

Calcium in those arteries is a marker of coronary atherosclerosis—the buildup of plaque in the coronary arteries.

The scan produces a number called a CAC score.

The higher the score, generally, the greater the amount of calcified coronary plaque and the higher the person’s cardiovascular risk.

And unlike a cholesterol test, which measures something circulating in your blood, a CAC scan gives you information about what’s actually happening in your coronary arteries.

That’s what makes it interesting.

Your LDL can look good while your arteries tell another story

LDL cholesterol is an important cardiovascular risk factor.

But it isn’t the only one.

Age, blood pressure, smoking, diabetes, family history, lipoprotein(a), inflammation and other factors can all contribute to cardiovascular risk.

The 2026 ACC/AHA dyslipidemia guideline now recommends using several pieces of information to estimate cardiovascular risk and says selective CAC testing can help reclassify risk when appropriate.

In other words, your LDL is one piece of the puzzle.

CAC can provide another.

What if your CAC score is zero?

This is one of the most interesting things about the test.

A CAC score of zero means no detectable calcified coronary plaque.

For appropriately selected people, that can substantially lower their estimated cardiovascular risk and may influence decisions about preventive medication.

The American Heart Association notes that CAC testing can be particularly useful when someone is uncertain about starting or restarting a statin.

But zero doesn’t mean “you have no plaque.”

CAC detects calcified plaque. It does not detect every type of coronary plaque, including noncalcified plaque.

So a zero score isn’t a lifetime guarantee that your arteries are free of disease.

What if your score is high?

That’s a different conversation.

A high CAC score indicates a greater burden of coronary atherosclerosis and can move someone into a substantially different risk category.

The 2026 guideline has expanded the role of CAC in helping guide LDL-lowering treatment and goals, including consideration of the absolute CAC score and the person’s age- and sex-adjusted percentile.

That’s important because two people with the same LDL number don’t necessarily have the same cardiovascular risk.

Their arteries may tell different stories.

But should every senior get one?

No.

And that’s an important part of the story.

CAC isn’t intended as a blanket screening test for everybody.

The American Heart Association says it can be useful when the treatment decision is uncertain, but it’s generally not appropriate when someone is very low-risk, when the treatment plan is already clear, or when someone already has known coronary artery disease.

It’s also not a test for someone experiencing symptoms such as chest pain that require a different type of evaluation.

So the question isn’t:

“Am I over 55? Should I get a CAC scan?”

It’s:

“Would knowing my CAC score change what I do?”

That’s a much better question.

Why age makes the question more interesting

CAC becomes more common as we get older.

That means finding some calcium in a 70-year-old isn’t necessarily surprising.

The number needs context.

That’s one reason the 2026 guideline emphasizes both the absolute CAC score and the standardized percentile when interpreting risk.

Interestingly, earlier ACC/AHA guidance specifically identified older adults—including men 55–80 and women 60–80 with a low burden of other risk factors—as people who might benefit from knowing if their CAC score is zero when they’re uncertain about statin treatment.

It’s not a test of whether you’re going to have a heart attack

This is another common misunderstanding.

A CAC scan doesn’t tell you:

“You will have a heart attack.”

And it doesn’t tell you:

“You’re going to be fine.”

It provides information about the burden of calcified coronary atherosclerosis, which can help estimate cardiovascular risk.

Think of it as another piece of evidence—not a crystal ball.

There’s also a downside

The scan uses a small amount of radiation.

And there’s another potential problem:

You can learn something without knowing what to do with it.

A result can create anxiety if there isn’t a clear plan for how it will change treatment.

That’s why CAC is most useful when the result is going to help answer a real question.

The American Heart Association says the scan generally takes only about 10–15 minutes, requires no special preparation, and typically costs around $50–$250 when not covered by insurance, although costs vary.

The question worth asking

Instead of asking:

“Is my LDL good?”

You might sometimes ask:

“How does my LDL fit into the bigger picture of my cardiovascular risk?”

For some older adults, a CAC scan can add valuable information to that picture.

For others, it may add very little.

And that’s why the most useful conversation isn’t about whether everyone should get a CAC scan.

It’s about whether you and your healthcare professional have an unanswered question that the scan could help answer.

The takeaway

Your LDL tells you something important.

But it doesn’t tell you everything.

A CAC scan can provide a glimpse of what’s actually happening inside your coronary arteries—and for some people 55 and older, that information can change the conversation about cardiovascular risk and prevention.

Sometimes the most useful health test isn’t the one that tells you what you already know.

It’s the one that answers a question you couldn’t answer before.