Most people learn they have heart disease when they have a heart attack. A scan that costs around $150 to $250 can find it years earlier. Here is what it shows, what it misses, and who should manage the result.

No new video this week. These two cover the background:

Here's the whole story 👇

I did not finish the whiteboard video this week. Clinic ran long and the weekend got away from me. Rather than send a rushed version, I want to tell you what has been on my mind instead.

I have ordered a number of CT calcium scans recently on patients with no symptoms. No chest pain, no shortness of breath, nothing. Some of those patients went and had the scan. Others listened and decided against it. Several came back showing significant heart disease.

Here is the problem in one sentence. A high LDL feels like nothing.

There is no symptom. Nothing hurts. So when a primary care physician or I tell someone their cholesterol needs to come down, we are asking them to treat a number that is not bothering them, for a benefit they will not immediately feel. Most people say no, and I understand why.

The trouble is that the damage has usually been building for decades. Autopsy studies found plaque already present in about a third of people aged 15 to 20, and in up to 70% of people aged 26 to 39 (Andersson & Vasan, Nat Rev Cardiol 2018). The average first heart attack comes at 65 in men and 72 in women (Rallidis et al, JACC 2022). That is roughly forty years of damage with no symptoms.

Many people never get a warning at all. In one study, heart attacks went completely unrecognized in 30% of affected women and 16% of men (van der Ende et al, J Am Heart Assoc 2020). The share of silent heart attacks rises from about 25% in younger patients to as high as 60% in people over 85 (Fleg et al, Circulation 2013).

A CT calcium scan looks for calcium in the walls of your heart arteries. That calcium sits inside old plaque that has hardened over time. It does not mean an artery is blocked right now. It means the disease has been going on long enough to leave a deposit you can see and count.

The test is easier for people to understand than a risk calculator that physicians use. It measures the disease itself instead of estimating your odds of having it.

Researchers pooled six studies covering 27,622 patients and sorted them by calcium score. The risk of dying from heart disease or having a heart attack climbs steadily as the score goes up.

A score of 0 is reassuring, but the reassurance has a time limit. Event rates run about 0.4% over three to five years. Most people who score 0 will still score 0 three to five years later. After that, many begin to show calcium. People at the lowest risk hold a score of 0 for about seven years. People with diabetes develop calcium considerably sooner (Dzaye et al, JACC Cardiovasc Imaging 2021).

A 2022 review in JAMA Internal Medicine measured how much the scan adds on top of a standard risk calculator. The added value was real, but smaller than many people assume. Among patients the standard calculator called low risk, only 0.4% to 2.2% were correctly moved into a higher risk category. Another 2.1% to 14.4% were moved up and never had a cardiac event. Of everyone the scan moved from low risk into a higher category, 85.5% to 96.4% had no cardiac event during the study period (Bell et al, JAMA Intern Med 2022).

Put simply: most people with an elevated score never have a heart attack.

The scan also cannot see soft plaque, which has not hardened yet. Up to 14% of people with a significant blockage score 0 (van der Bijl et al, Lancet 2025). Under age 40 the test usually returns 0, because calcium has not formed yet. And the national guideline describes it as a tool for patients whose treatment decision is genuinely uncertain, not a test everyone should have (Arnett et al, JACC 2019).

The scan uses about 1 mSv of radiation, roughly the same as one or two mammograms. It identifies unrelated findings, such as a small spot on the lung, in fewer than 10% of cases.

This is the most useful thing the 2026 national cholesterol guideline did. It applies to men 40 and older and women 45 and older who fall in the middle of the risk range, with an LDL between 70 and 189.

One important exception. A score of 0 does not change the recommendation if you have inherited high cholesterol, an LDL above 190, diabetes, current tobacco use, or a strong family history of early heart disease. In inherited high cholesterol, the scan should not be used to defer treatment at all.

A calcium score is information, not a treatment plan. My job is to help patients understand their risk. Deciding what to do about it belongs with the physicians who manage heart disease every day→ cardiologists. Ordering a test and managing the result are two different jobs, and I try to stay clear about which one is mine.

In practice, the results have changed care in two ways.

The first is in men with aggressive prostate cancer. Hormone therapy, called androgen deprivation therapy, is often part of their treatment. It works, and it also raises cardiovascular risk. A review of about 400,000 patients found a 38% higher risk of a fatal or nonfatal cardiac event on these medications, with heart attack risk up 57% and stroke risk up 51% (Cereda et al, Heart Fail Rev 2022). The risk is highest in the first six months, and highest of all in men who have already had two or more cardiac events. In men whose prostate cancer has not spread, heart disease is the most common cause of death, accounting for 23% of deaths compared with 17% from the cancer itself (Okwuosa et al, Circ Genom Precis Med 2021).

So when a calcium scan comes back high in a man about to start hormone therapy, it changes the conversation. It does not change whether he needs cancer treatment. It changes who else is involved in planning it. European guidelines already recommend assessing cardiovascular risk before starting these medications, and a cardiology consultation for older men with a history of heart disease (Lyon et al, Eur Heart J 2022).

The second is in middle aged adults with no cancer at all. High scores have led me to refer several of these patients to cardiology, and that is the right outcome. I can order the test and explain what the number means. A cardiologist decides whether someone needs further testing, a different medication, or a closer look at the arteries.

If you take one thing from this issue, take this. Ask your own physician whether the test makes sense for you. If the number comes back high, ask to see a cardiologist.

You probably know someone in their fifties or sixties whose doctor mentioned their cholesterol once and never followed up. Please forward this to them. A scan and a real conversation with their own physician are worth having before the disease shows up on its own. That's how Pareto Life grows.

Next issue, I will have the whiteboard video finished, and we will walk through what a calcium score looks like scan by scan.

References

Glynn, Khan & Greenland, JAMA 2025 · Bell et al, JAMA Intern Med 2022 · Blumenthal et al, JACC 2026 · Expert Panel on Cardiac Imaging, JACR 2021 · Greenland et al, JACC 2010 · Arnett et al, JACC 2019 · van der Bijl et al, Lancet 2025 · Dzaye et al, JACC Cardiovasc Imaging 2021 · Orringer et al, J Clin Lipidol 2020 · Patel et al, Int J Cardiovasc Imaging 2019 · Rallidis et al, JACC 2022 · Andersson & Vasan, Nat Rev Cardiol 2018 · van der Ende et al, J Am Heart Assoc 2020 · Fleg et al, Circulation 2013 · Cereda et al, Heart Fail Rev 2022 · Okwuosa et al, Circ Genom Precis Med 2021 · Lyon et al, Eur Heart J 2022