EARLY DETECTION
Coronary Calcium Score: A Guide to the Heart Scan Test
31 July 2025
Written by
Sven Jaeschke, PhD
Reviewed by
In the world of proactive health, particularly in the US, a key metric is creating a buzz among longevity doctors and tech leaders: the Coronary Artery Calcium (CAC) score. It's a number that offers a direct, powerful glimpse into the health of your heart's arteries, moving beyond traditional risk factors to show the actual, accumulated story of your cardiovascular health.
But what is this scan, and why is it gaining so much attention?
A CAC score provides a unique glimpse "under the hood," offering a clear, quantitative measure of your accumulated risk for cardiovascular disease. While it has gained significant traction in the United States as a fundamental tool for personalized prevention, it remains less common in Europe as a self-directed screening tool. At Ahead, we believe in making this powerful technology accessible, but in a way that is medically rigorous and responsible.
This article is your guide to understanding this pivotal health metric. It’s not about creating anxiety; it’s about empowerment. By the end, you will understand what a calcium score is, what it reveals about your health, who can benefit from it, and most importantly, what you can do with that knowledge. This is the core of our philosophy at Ahead: providing you with the data you need to take decisive, proactive control of your health journey.
A look inside your arteries: what is a calcium score?
To grasp the significance of a calcium score, we first need to understand the process it measures: atherosclerosis. It’s a term many have heard, but few truly understand beyond a vague notion of "clogged arteries."
The root of the problem: atherosclerosis explained simply
Atherosclerosis is much more than simple plumbing blockage. It is a chronic, low-grade inflammatory disease that occurs within the delicate inner walls of our arteries. Over decades, substances like cholesterol, fats, and cellular waste products can accumulate in the artery wall, forming a deposit known as plaque.
Think of your artery wall as the smooth plaster on a wall in your home. Atherosclerosis begins with tiny, invisible cracks and damage to that plaster, often caused by risk factors like high blood pressure, smoking, or elevated levels of certain lipoproteins. In response to this damage, your body initiates a repair process. This process involves inflammation, where immune cells rush to the site of injury and smooth muscle cells start to migrate and proliferate within the inner layers of the blood vessels. Over time, this ongoing repair effort can become dysfunctional if the inflammation isn’t controlled. The "patch" that forms—the plaque—is a complex mixture of lipids, inflammatory cells, and fibrous tissue.
What is calcification and why does it matter?
As these plaques mature over many years, the body often deposits calcium into them as a way to stabilize the area. This calcification is a late-stage marker of the disease process.16 The calcium itself is not the primary danger; rather, its presence is a definitive, unmistakable sign that atherosclerosis has been present for some time. It is a historical scar, a footprint left behind by years of underlying arterial disease.
A Coronary Artery Calcium (CAC) score is a direct measurement of this calcified plaque. It provides a historical record of the cumulative "wear and tear" on your coronary arteries, the critical vessels that supply your heart muscle with oxygen-rich blood. It quantifies the total burden of this hardened plaque, giving you a tangible number that reflects your personal history of cardiovascular disease.
The scan itself: a quick and simple process
Getting a calcium score is a remarkably straightforward and fast procedure. It involves a specialized type of X-ray called a computed tomography (CT) scan, but it is much simpler than many other imaging tests.
The entire process typically takes only 10 to 15 minutes. You will lie comfortably on a table that slides into a large, donut-shaped scanner. Small, sticky electrodes will be placed on your chest to monitor your heart's electrical activity with an electrocardiogram (ECG). This allows the scanner to time its pictures between heartbeats, when the heart muscle is most still, ensuring the images are crystal clear.
You will be asked to hold your breath for a few seconds while the images are taken. The scan is completely non-invasive; there are no injections, no needles, and no contrast dye is used. It is a simple, painless snapshot of your coronary arteries.
Decoding your results: understanding the Agatston score
After the scan, a sophisticated computer program analyzes the images to detect and quantify any areas of calcification. The result is expressed as a number known as the Agatston score, named after Dr. Arthur Agatston, the cardiologist who pioneered this method. This score reflects both the total area and the density of the calcified plaque found in your coronary arteries.
Breaking down the numbers
The score can range from zero to over a thousand, and it is generally categorized into levels of risk. Understanding where your score falls is the first step in turning this data into action.
Agatston Score | Associated Risk Level | What It Means in Simple Terms |
|---|---|---|
0 | Very Low Risk | No calcified plaque was found. Your risk of a heart attack in the next 5-10 years is extremely low. |
1-10 | Low Risk | A minimal amount of plaque is present. Your risk of a heart attack in the next 5-10 years is low. |
11 - 100 | Mild Risk | A small amount of plaque is present. This is the earliest definitive sign of coronary artery disease. |
101 - 400 | Moderate Risk | A moderate amount of plaque is present. You have established coronary artery disease and a higher risk of a future heart attack. |
> 400 | High Risk | An extensive amount of plaque is present. Your risk of a heart attack is high, and significant blockages are more likely. |
The importance of context: percentile scores
While the absolute Agatston score is powerful, it tells only part of the story. To truly personalize your risk, this number is often converted into a percentile rank. This percentile compares your score to the scores of other people of the same age, gender, and ethnicity.
Context is everything. For example, a calcium score of 50 in a 70-year-old man might place him in a low percentile for his peer group, suggesting his plaque burden is less than expected for his age. However, the exact same score of 50 in a 45-year-old woman would be highly concerning, placing her in a very high percentile and indicating accelerated, premature atherosclerosis. This is why discussing your results with a physician is crucial; they can interpret your score not just as a number, but as a personalized indicator of your unique health trajectory.
The power of a number: why your score matters
Traditional methods for assessing heart disease risk, such as the Framingham or SCORE2 calculators, rely on a cluster of risk factors like age, cholesterol levels, blood pressure, and smoking status. While useful for populations, they are often imprecise at predicting an individual's actual risk. Many people who suffer heart attacks fall into the "low" or "intermediate" risk categories based on these calculators. The CAC score cuts through the statistical noise.
A more accurate predictor
For individuals without symptoms of heart disease, the CAC score has proven to be one of the most powerful independent predictors of future heart attacks and strokes. Large, long-term studies like the Multi-Ethnic Study of Atherosclerosis (MESA) have shown that adding a CAC score to traditional risk factors significantly improves the accuracy of risk prediction. It moves you from a statistical probability to a direct observation of the disease itself.
The 'power of zero': a 15-year warranty?
One of the most profound findings in preventative cardiology is the "power of zero." A CAC score of 0 is an incredibly strong negative risk marker. It indicates that, despite any other risk factors you may have (like high cholesterol or a family history of heart disease), your personal 10-to-15-year risk of a major cardiac event is extremely low.
This finding has been described as a "15-year warranty" against a fatal heart attack. For individuals who are on the fence about starting lifelong medications like statins, a score of zero can provide powerful reassurance and support a shared decision with their doctor to focus on lifestyle interventions instead. It allows for a more nuanced and personalized approach to prevention, avoiding potential overtreatment in those with a very low actual disease burden.
The nuance of zero: not a perfect shield
While a score of zero is exceptionally good news, it's crucial to understand its limitations. A CAC scan detects calcified, or hardened, plaque. It does not detect "soft," non-calcified plaque, which is an earlier stage of the disease and can also be dangerous.
This is particularly relevant for younger individuals. A 40-year-old may have a significant amount of soft plaque that simply hasn't had time to calcify yet. In this case, a score of zero might offer false reassurance. Therefore, a zero score is not a license to ignore critical risk factors. If you are a smoker, have diabetes, or have extremely high levels of atherogenic lipoproteins (like LDL-C or ApoB), these factors still require aggressive management, regardless of your calcium score. A zero score is most powerful when it confirms a low-risk profile and becomes increasingly reassuring as you age.
A non-zero score: a motivator, not a verdict
Receiving a score greater than zero can be unsettling, but it should be viewed as a definitive and highly motivating call to action, not a final verdict. It transforms abstract risk factors into tangible proof of disease. For many, seeing that number is the catalyst they need to make meaningful and lasting changes.
Studies have shown that when patients are aware of their calcium score, they are significantly more likely to adhere to lifestyle modifications and prescribed medications. The number makes the risk real. It provides a clear "why" for taking a statin, changing your diet, or committing to an exercise routine. It turns prevention from a vague concept into a concrete, personal mission.
Is a calcium scan right for you? A European perspective
With its clear predictive power, it's natural to ask if everyone should get a calcium scan. The answer, according to major medical guidelines, is no. The test is most valuable for a specific group of people.
The ideal candidate: the 'intermediate risk' individual
Both the American College of Cardiology/American Heart Association (ACC/AHA) and the European Society of Cardiology (ESC) agree that the CAC score is most useful for asymptomatic adults, typically between the ages of 40 and 75, whose risk of heart disease is uncertain.
This is often referred to as the "intermediate risk" category. These are individuals where traditional risk calculators don't give a clear answer. Their risk isn't low enough to confidently forgo treatment, but it's not high enough to make lifelong medication an obvious choice. In this scenario, the CAC score serves as an incredibly effective tie-breaker, reclassifying a substantial number of people into either a lower-risk group (where medication may be deferred) or a higher-risk group (where treatment is clearly beneficial).
A quick checklist: is this scan for you?
Consider if several of the following apply to you:
Are you a man over 40 or a woman over 50?
Do you have risk factors like high cholesterol, high blood pressure, diabetes, or a history of smoking?
Do you have a family history of early heart disease? 7
Are you currently without symptoms (like chest pain or shortness of breath)?
Are you and your doctor uncertain about whether you should start a medication like a statin?
If you answered "yes" to several of these questions, a calcium scan could provide valuable clarity.
Who should NOT get a scan?
To build trust and ensure responsible care, it's just as important to know who the test is not for. A CAC scan is generally not recommended for:
Symptomatic patients: If you are experiencing symptoms like chest pain, pressure, or shortness of breath with exertion, a CAC score is not the right test. You need urgent medical evaluation and likely a different type of test (like a stress test or CT angiogram) to look for active blockages.
High-risk patients: If you have already had a heart attack, have a coronary stent, or have undergone bypass surgery, you have known heart disease. Your risk is already considered very high, and you should be on aggressive medical therapy. A CAC score will not add any new information to your treatment plan.
Very low-risk patients: If you are young (e.g., under 40) and have no significant risk factors for heart disease (no smoking, no diabetes, healthy blood pressure and cholesterol, no strong family history), you are extremely unlikely to have any coronary calcium. A scan would provide little value and result in unnecessary radiation exposure.
The European context: a more considered approach
The difference in the adoption of CAC scoring between the US and Europe can be largely explained by differences in official medical guidelines. The ACC/AHA guidelines in the US give CAC scoring a strong (Class IIa) recommendation for helping to guide statin therapy decisions in intermediate-risk individuals.
The European Society of Cardiology (ESC) guidelines have historically been more conservative. They acknowledge the test's value but recommend it as a "risk modifier" in borderline cases (Class IIb), meaning it can be considered to refine risk but is not as central to the decision-making process. This more cautious stance has contributed to lower adoption in Europe.
However, the scientific evidence supporting the predictive power of the CAC score is robust and universal. This creates an opportunity to bridge the gap. At Ahead, we embrace this challenge by offering direct access to this advanced preventative tool, but within a framework of rigorous medical oversight that aligns with the thoughtful European clinical culture.
The Ahead process: safety, precision, and physician guidance
When considering any medical test, especially one involving radiation, safety and expert guidance are paramount. Our process is designed to maximize the benefits of the scan while ensuring it is used appropriately and responsibly.
The radiation question: putting a small risk in perspective
It is true that a CAC scan uses a CT scanner, which involves ionizing radiation. However, it is a very low-dose scan. A modern CAC scan delivers a radiation dose of approximately 1-3 millisieverts (mSv).
To put that number into perspective:
Annual background radiation: We are all constantly exposed to natural "background" radiation from sources like the sun and the earth. The average person receives about 3 mSv of background radiation per year. A single CAC scan is roughly equivalent to one year of this natural exposure.
Comparison to other scans: The dose is comparable to that of a screening mammogram. It is significantly lower than a standard diagnostic chest CT (around 7 mSv) or a coronary CT angiogram (which can be 5-12 mSv or more).
Air travel: While often used as a comparison, the radiation from a single flight is very small (a 7-hour flight is about 0.02 mSv). The more meaningful comparison is to the radiation you naturally absorb just by living on Earth for a year. The risk is considered very small, but it is not zero, which is why the test should only be performed when the potential benefit of the information outweighs this minimal risk.
The Ahead difference: medically guided prevention
This brings us to a critical part of the Ahead process. In line with best practices in Europe, we believe that any scan involving radiation should be medically justified. That is why, as part of our booking process, it is mandatory for one of our physicians to review your risk profile and medical history before a CT scan can be performed.
This is not a barrier; it is a vital safety measure. This physician review ensures that the scan is appropriate for you and that you are not being exposed to radiation unnecessarily. It prevents a very low-risk individual from getting a scan they don't need, and it helps direct a symptomatic person towards a more appropriate medical evaluation. At Ahead, we manage this entire process for you, making proactive care both seamlessly accessible and fundamentally safe.
You have your score. Now, take control.
Receiving your calcium score is the beginning of a new, more informed chapter in your health journey. It is a powerful piece of data that, when combined with expert guidance, allows you to create a truly personalized action plan. A crucial point to remember is that while the calcified plaque itself is generally not reversible, the risk it represents is absolutely manageable. The goal is not to lower the score, but to lower your future risk by stabilizing existing plaque and preventing new plaque from forming.
Here is a general guide to what your score might mean for your next steps.
If your score is 0
Action: First, take a moment to appreciate the powerful reassurance this result provides. Your immediate risk is very low. The primary focus should be on maintaining the healthy habits that have led to this excellent result.
Nuance: Remember the limitations. If you have significant risk factors like active smoking, diabetes, a strong family history of premature heart disease, or very high ApoB/LDL cholesterol, a zero score does not give you a free pass. A conversation with your doctor about managing these specific risks is still essential.
Next steps: For most people with a zero score and low-to-intermediate risk, repeating the scan in 5 to 7 years is a reasonable strategy to ensure you remain in the low-risk category. If you have ongoing risk factors, your doctor might suggest a repeat scan in 3 to 5 years.
If your score is 1-100 (mild risk)
Action: This score is an early warning sign. It confirms that the process of atherosclerosis has begun. This is an incredibly powerful motivator to double down on lifestyle optimization. This is the ideal time to make changes that can have a profound impact on your future health. Key areas of focus include:
Nutrition: Adopting a Mediterranean-style diet rich in vegetables, fruits, nuts, seeds, and healthy fats like olive oil.
Exercise: A consistent routine including at least 150 minutes of moderate-intensity aerobic exercise (like brisk walking or cycling) and two sessions of strength training per week.
Lifestyle: Prioritizing 7-9 hours of quality sleep, managing stress, and eliminating tobacco use are non-negotiable.
Next steps: A detailed discussion with your doctor is crucial. Based on your overall risk profile and percentile score, you may be a candidate for statin therapy. The 2018 ACC/AHA guidelines suggest that statin therapy is favored in this group, especially for those over age 55.
If your score is 101-400 (moderate risk)
Action: This score indicates that you have established coronary artery disease. Aggressive and comprehensive risk factor modification is now the priority. The lifestyle changes mentioned above are no longer just preventative; they are a core part of your treatment.
Next steps: Medical therapy is almost always recommended. This will typically involve starting a statin to lower your LDL cholesterol, which helps to stabilize plaque and reduce inflammation in the arteries. Your doctor may also discuss initiating low-dose aspirin therapy, balancing its blood-thinning benefits against any potential bleeding risks. A comprehensive plan to manage blood pressure and blood sugar, if elevated, is also essential.
If your score is >400 (high risk)
Action: A score in this range signifies an extensive plaque burden and a high risk of a future cardiac event. This requires an intensive partnership with your medical team to aggressively manage your risk.
Next steps: High-intensity statin therapy is a cornerstone of treatment. Your doctor will work with you to achieve very low LDL cholesterol targets, potentially using additional medications if needed. Given the high plaque burden, your doctor may also recommend further testing, such as a cardiac stress test or a coronary CT angiogram (CCTA), to determine if any of the plaque is causing a significant blockage (stenosis) that might be impeding blood flow to the heart muscle. This helps determine if more advanced interventions are needed.
Calcium scoring in a holistic health plan
A calcium score is an incredibly powerful data point, but it is still just one piece of a much larger puzzle. True proactive health comes from a holistic, multimodal view.
For example, combining a calcium score with a radiation-free full-body MRI provides unparalleled insight into your organs, brain health, and body composition, including a precise quantification of visceral fat, which is another key driver of cardiovascular risk. When this imaging data is further integrated with comprehensive blood biomarker panels, which measure not just standard cholesterol but advanced cardiovascular markers like Apolipoprotein B (ApoB), Lipoprotein(a) (Lp(a)), and high-sensitivity C-reactive protein (hs-CRP), a truly 360-degree view of your health emerges. This allows for a deeply personalized and effective action plan designed to extend not just your lifespan, but your healthspan.
Conclusion
