A raised result is often the beginning of a positive and meaningful conversation about your heart health.
The coronary artery calcium (CAC) score is a CT scan that detects and measures calcified plaque in the walls of the coronary arteries. It produces a number — the Agatston score — that reflects the total amount of calcium detected.
Calcium in the arteries is a marker of atherosclerosis — the process by which plaque builds up in artery walls over time. A higher score generally indicates more plaque has accumulated. However, and this is critically important, the score tells you about calcified plaque only. It says nothing about soft, non-calcified plaque, which can be equally or more dangerous.
The test is quick, non-invasive and involves a low dose of radiation. It takes only a few minutes and requires no contrast dye or injections. It is most useful as a risk-stratification tool — helping doctors decide how aggressively to manage cardiovascular risk factors.
The calcium score is one piece of information — not a verdict. It should always be interpreted in the context of your full cardiovascular risk profile, including blood pressure, cholesterol, smoking history, family history, diabetes, LP(a) and other factors. A number in isolation means very little.
If your GP ordered this test without a thorough discussion of your overall risk profile, ask for a referral to a cardiologist who can interpret the result in the context of your full clinical picture. The number alone is not enough.
"A calcium score is one piece of a much larger picture. The number alone is never the whole story — a score of zero does not rule out significant disease, and a very high score does not mean a heart attack is imminent. What matters is understanding your complete risk profile, addressing what can be changed, and moving forward with a clear plan. This number is not a sentence. It is the start of a conversation."
Professor Peter Barlis
Interventional Cardiologist & Founding Editor, Heart Matters
The Agatston score is divided into ranges that correspond broadly to levels of coronary artery disease burden. Remember — these are guides, not diagnoses. Your cardiologist will interpret your score alongside your full risk profile.
No calcium detected. Associated with a low short-term risk of cardiac events — but does not mean zero risk. Soft plaque can still be present and is invisible to this scan.
Mild coronary artery calcification. Some plaque burden present. Risk management and lifestyle optimisation are important. Medication may or may not be indicated depending on your full risk profile.
Moderate plaque burden. A more proactive approach to risk factor management is warranted. This does not mean you have significant blockages — it means the process of plaque accumulation is underway and needs to be addressed.
Significant calcification present. Warrants thorough risk factor assessment and a proactive management plan. Does not automatically mean blockages are present or that intervention is needed — context and clinical assessment are essential.
Calcium scores should always be interpreted relative to age and sex. A score of 100 in a 45-year-old is more significant than the same score in a 75-year-old. Percentile rankings — where your score sits relative to others of the same age and sex — can be a more meaningful guide than the raw number alone.
The calcium score is one of the most misunderstood tests in cardiology. These misconceptions cause unnecessary anxiety — and sometimes dangerous complacency. Here is the truth.
A high calcium score means I have a major blockage and need a stent.
A high score indicates significant calcified plaque burden — but plaque in artery walls does not necessarily cause a blockage of the lumen. Most people with elevated scores do not need intervention. Management focuses on stabilising plaque and reducing further accumulation.
A score of zero means I am safe and have no heart disease risk.
A zero score is reassuring but not a guarantee of safety. Soft, non-calcified plaque — which is actually more prone to rupture — is invisible to calcium scoring. People with a zero score can still have a heart attack. Risk factors still need to be managed.
The calcium score tells me everything I need to know about my heart health.
The calcium score is one tool among many. A full cardiovascular assessment should include blood pressure, cholesterol panel including LP(a), blood sugar, family history, smoking status, kidney function and ideally a clinical assessment by a cardiologist.
My score went up — that means my treatment isn't working.
Not necessarily. Statins in particular can cause the calcium score to increase — but this is actually a sign the medication is working. See the section below to understand why a rising score on statins can be good news.
This is one of the most common questions I receive — and the answer is clear.
The metallic density of a stent creates significant artefact on the scan, making the result uninterpretable. A calcium score cannot reliably distinguish stent material from calcified plaque in this setting — the numbers produced are simply not meaningful.
For patients with stents who need further coronary imaging, a CT coronary angiogram may offer more useful information in selected cases — though this decision is always individualised and depends on the clinical question being asked. Speak with your cardiologist about what imaging, if any, is appropriate for your specific situation.
This surprises almost everyone — including many doctors. If you are on a statin and your calcium score has gone up, your first instinct might be to assume the medication isn't working. In many cases, the opposite is true.
Statins work by reducing LDL cholesterol and stabilising atherosclerotic plaques. Part of this stabilisation process involves calcification — the body lays down calcium within the plaque, forming a harder, more stable cap that is less likely to rupture.
When a plaque ruptures, it triggers the formation of a blood clot — which is what causes a heart attack. A calcified, stable plaque is far safer than a soft, lipid-rich plaque with a thin fibrous cap. So paradoxically, the calcium score going up can reflect that plaques are being stabilised and hardened.
This does not mean statins are right for everyone. The decision to prescribe them should always be individualised — based on your full risk profile, not simply on your calcium score number.
Calcium score progression on statin therapy does not necessarily mean treatment failure. The goal of statins is not to lower the calcium score — it is to reduce cardiovascular events by stabilising plaque and lowering LDL. Always discuss any change in your score with your cardiologist before making decisions about your medication.
Statins are among the most discussed, and most misunderstood medications in cardiovascular medicine. The evidence for their benefit in the right patients is robust. However they are not universally indicated, and the decision should always be personalised. If you have concerns about your statin prescription, please discuss them with your cardiologist.
A calcium score, whatever the number, is an opportunity, not a sentence. It is a chance to take stock of your cardiovascular health and act proactively. Click each step to learn more.
If your result was not discussed in depth by a cardiologist, ask your GP for a referral. The score needs to be interpreted alongside your full risk profile — not just handed to you with a percentage figure. A cardiologist can put the number in context and guide next steps.
Blood pressure, cholesterol, blood sugar, kidney function, BMI, smoking status — all need to be assessed together. Ask specifically about LP(a), as it is a significant cardiovascular risk factor that is often not checked as part of a routine blood panel but can be highly relevant to your overall picture.
A strong family history of early heart disease significantly changes the interpretation of your score. Genetic factors including familial hypercholesterolaemia and elevated LP(a) are important considerations that are often overlooked. Discuss your family history with your cardiologist.
The evidence for lifestyle modification is overwhelming. Regular physical activity, a heart-healthy diet, stress management, good sleep and maintaining a healthy weight all reduce cardiovascular risk independently of medication. These are not optional extras — they are foundational to any management plan regardless of your score.
Statins, blood pressure medications and other agents may be appropriate depending on your full risk profile. The decision should always be individualised — not based solely on a calcium score number or a generic risk percentage. You deserve a personalised conversation with your cardiologist about what is right for you.
In some cases, a CT coronary angiogram (CTCA) may be recommended to look at the inside of the artery wall and assess whether any significant narrowings are present. This is not always necessary but can provide valuable additional information in selected patients. Your cardiologist will advise whether this is appropriate for you.
Elevated LDL cholesterol is one of the primary drivers of atherosclerosis. The right target for you depends on your overall risk profile — not a one-size-fits-all number. Talk to your cardiologist about what your personal cholesterol target should be and whether treatment is appropriate.
Hypertension is one of the most powerful drivers of cardiovascular risk. Even modest reductions in blood pressure translate into meaningful reductions in heart attack and stroke risk. Your healthcare professional can advise on the best approach for you.
If you have diabetes or pre-diabetes, blood sugar management is a key part of your cardiovascular risk reduction. Newer medications have shown heart benefits beyond glucose lowering. Have a conversation with your doctor about what optimal control looks like for you personally.
Stopping smoking is the single most impactful thing you can do for your cardiovascular health regardless of your calcium score. The benefit begins almost immediately. Support is available — talk to your GP about cessation programmes if you need help.
Regular physical activity, a heart-healthy diet, maintaining a healthy weight and reducing alcohol intake all contribute meaningfully to cardiovascular risk reduction. These are foundational — not optional. Your healthcare professional can advise on what level of activity is appropriate for you.
LP(a) is a genetically determined lipoprotein that can significantly raise cardiovascular risk. It is not part of a standard cholesterol panel and is often missed. If you have an elevated calcium score or a strong family history of heart disease, ask your doctor specifically whether LP(a) testing is appropriate for you.
Atherosclerosis can affect multiple vascular territories. Depending on your result and risk profile, your healthcare professional may consider whether additional tests are useful. Have a conversation about whether any further evaluation makes sense for your individual circumstances.
Stress, poor sleep, anxiety and conditions such as sleep apnoea are all recognised contributors to cardiovascular risk that are often overlooked. If any of these are relevant to you, they are worth discussing with your healthcare professional as part of a holistic approach to heart health.
The coronary artery calcium scan is one of the simplest and quickest cardiac tests available. Here is what to expect.
You will lie on a table that slides through a CT scanner — an open, doughnut-shaped machine. No injections, no contrast dye and no catheters are required. ECG leads are attached to synchronise the scan with your heartbeat. The scan itself takes less than 10 minutes from start to finish.
The radiation dose is low — typically around 1–3 mSv, roughly equivalent to several months of natural background radiation. For context, a CT coronary angiogram (CTCA), which provides more detailed information about the inside of the artery, involves a somewhat higher dose — typically 3–10 mSv — but still well within accepted safety parameters.
The CAC scan detects calcium in artery walls and gives you a score. The CT coronary angiogram (CTCA) uses contrast dye to visualise the inside of the artery — showing whether any narrowings are actually present. They answer different questions. Your cardiologist will advise which is appropriate for your situation.
No special preparation is usually required for a CAC scan. You may be asked to avoid caffeine beforehand as it can affect heart rate. Wear comfortable clothing and avoid jewellery around the chest area. The entire appointment is typically 20–30 minutes.
You can resume normal activities immediately. Results are usually available within a few days. If your score is elevated, ensure you discuss it with a cardiologist — not just a printout with a risk percentage. The context and interpretation matter enormously.
In this video, Professor Barlis walks through what the coronary calcium score means, how to interpret your number, and what steps to take next.
If your calcium score has raised questions about stents, this book is for you. Professor Peter Barlis guides patients and families through every stage of the heart stent journey — from understanding why a stent may be needed, through the procedure itself and recovery. Written in plain language with clinical depth.
Buy on Amazon →These articles from Heart Matters explore topics closely related to your calcium score result.
The content on heartmatters.com is for general educational purposes only and is not a substitute for medical advice. Always consult your doctor or a qualified healthcare professional about any medical concerns. Calcium score results should always be interpreted by a qualified clinician in the context of your full cardiovascular risk profile.