Coronary Calcium and Cardiovascular Aging: What Makes Plaque Progress—and What a Scan Can Really Tell You

Edited and Approved by Stephen C. Rose, PhD, MS

Coronary artery disease often advances for years without chest pain or another obvious warning. A coronary artery calcium scan can reveal one trace of that hidden process: calcium embedded within plaque in the walls of the heart's arteries. The result is not a crystal ball, and it does not measure how much calcium a person eats. It is a marker of atherosclerosis—the long biological history of cholesterol, inflammation, repair, and scarring inside an artery.

A landmark analysis from the Multi-Ethnic Study of Atherosclerosis, or MESA, helped clarify which factors were associated with the appearance and growth of coronary calcium in people who had no symptoms of cardiovascular disease [1]. Its central lesson remains useful: arterial aging is measurable, but the number must be interpreted in the context of the whole person.

What a coronary calcium score measures

The test is a quick, noncontrast CT scan synchronized with the heartbeat. Areas of calcium in the coronary arteries are identified and combined into an Agatston score. A score of zero means no calcified coronary plaque was detected. Higher scores indicate a greater burden of calcified plaque. The score is useful for estimating risk, but it is not the same as the percentage narrowing of an artery, and it does not show blood flow or describe every plaque feature [2].

Calcification is best understood as a footprint of atherosclerosis. Calcium can accumulate as plaques mature and the artery repeatedly responds to injury. That makes the scan more directly connected to a person's lifetime plaque burden than a single cholesterol measurement, yet less suitable for explaining exactly when or why each plaque formed. A high score signals disease burden; it does not identify which plaque, if any, will cause an event.

What the original MESA progression study found

The 2007 MESA report followed 5,756 adults who had two calcium scans an average of 2.4 years apart. Among participants without detectable calcium at the first scan, new calcium appeared at an average rate of 6.6% per year. Age mattered substantially: annual incidence was below 5% in people younger than 50 and above 12% in those older than 80. Among people who already had calcium, the median annual increase was 14 Agatston units in women and 21 in men [1].

Older age, male sex, hypertension, higher body mass index, diabetes, higher glucose, and a family history of heart attack were associated with the development or progression of calcium. Associations also differed across the race and ethnicity categories used in the study. Those categories should not be mistaken for simple biological explanations: they can reflect ancestry, environment, access to care, discrimination, socioeconomic conditions, and other exposures that the scan itself cannot separate.

This was an observational study. It can identify patterns but cannot prove that changing one measured factor will produce a particular change in calcium. The participants were also free of clinically apparent cardiovascular disease at enrollment, so the results should not be applied uncritically to someone with known coronary disease, prior bypass surgery, a stent, or active symptoms.

Why progression matters—but is not the whole story

Later MESA research connected calcium progression with outcomes. Among people who underwent repeat scanning, greater increases in calcium were associated with a higher subsequent risk of coronary heart disease events [3]. A separate analysis with about a decade of follow-up found a graded relationship between the baseline score and cardiovascular events across age, sex, and racial or ethnic groups. Scores above 100 generally identified risk above commonly used treatment thresholds, while a score of zero was usually associated with low 10-year risk [4].

That does not make the change between two scans a simple report card. A rising number may reflect a higher total burden, normal evolution of existing plaque, differences between scanners or scan technique, and the effects of treatment on plaque composition. Clinical decisions should not be made from the arithmetic of two scores alone.

What a score of zero can—and cannot—mean

A zero score is genuinely reassuring in many asymptomatic adults. In MESA, it was a stronger negative risk marker than several other commonly discussed tests and risk characteristics [5]. In an appropriate patient, that information can support a more personalized discussion about whether medication is likely to provide enough benefit to justify taking it now.

Zero is not the same as zero risk. Calcium scanning does not reliably detect soft, noncalcified plaque, which can be more common in younger people and in earlier disease. A 2024 systematic review estimated that roughly 10% of asymptomatic people with a calcium score of zero had some noncalcified plaque on coronary CT angiography, although obstructive noncalcified plaque was much less common, at about 1% [6]. Symptoms, strong risk factors, or a clinician's concern must not be dismissed because the calcium score is zero.

Who may benefit from the scan

The 2026 American College of Cardiology and American Heart Association dyslipidemia guideline treats calcium scanning as a selective decision aid, not a universal screening test. It can be useful when an adult's estimated risk is borderline or intermediate and there is still uncertainty about starting or intensifying cholesterol-lowering treatment. The guideline specifically discusses its use beginning at age 40 in men and age 45 in women when the result could change the treatment conversation [7].

Recent MESA work suggests the score may also improve risk classification in some adults initially labeled low risk [8]. That is an important research direction, but it does not mean every low-risk person needs a scan. Testing is most valuable when the result would lead to a different, evidence-based action. It adds little when treatment is already clearly indicated, clearly inappropriate, or unwanted regardless of the result.

The statin paradox and repeat scanning

One of the easiest mistakes is to assume that any increase in calcium proves treatment has failed. Statins lower cardiovascular event risk, but they can also promote a denser, more calcified appearance as plaque stabilizes. In the PARADIGM study, calcium progression tracked plaque components differently in statin users than in people not taking statins [9]. A rising score during statin therapy therefore cannot be read as a direct measure of growing dangerous plaque.

For the same reason, routine serial scanning is not an automatic requirement. A repeat scan exposes a person to more radiation and may create anxiety without changing management. If a clinician and patient are considering another scan, they should first ask what decision the new number would resolve, how long it has been since the first scan, whether risk factors have changed, and whether treatment is already underway.

Benefits, limitations, and practical action

Modern calcium scanning uses a relatively low radiation dose. In MESA, the average effective dose with contemporary scanners was approximately 1 millisievert, though dose varies with equipment and body size [10]. Other limitations include cost, incidental findings outside the coronary arteries, false reassurance after a zero score, and possible overtreatment or worry after a high score. The test is intended for risk assessment in selected people without symptoms; new chest pressure, shortness of breath, fainting, or other concerning symptoms require clinical evaluation, not a screening calcium scan.

Whatever the score, the foundations of prevention remain familiar: avoid tobacco, manage blood pressure and diabetes, treat elevated LDL cholesterol when indicated, stay physically active, protect sleep, and follow an eating pattern rich in minimally processed plant foods. A high score may strengthen the case for intensive prevention, but it does not identify a supplement that dissolves calcium. Calcium in food and appropriate calcium supplements are not established causes of a high coronary calcium score; medication and supplement decisions should be individualized.

The bottom line

Coronary calcium is a visible record of otherwise silent atherosclerosis. The MESA study showed that its appearance and progression track age and familiar cardiovascular risk factors, and later research linked greater burden and progression with future events. Used selectively, the scan can sharpen a prevention decision. It should never be treated as a diagnosis by itself, a reason to ignore symptoms, or a score to chase from year to year. The useful question is not simply, “What is my number?” but, “Will this number help me make a better prevention decision?”

References

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[2] Alluri K, Joshi PH, Henry TS, et al. Scoring of coronary artery calcium scans: history, assumptions, current limitations, and future directions. Atherosclerosis. 2015;239(1):109-117. doi:10.1016/j.atherosclerosis.2014.12.040.

[3] Budoff MJ, Young R, Lopez VA, et al. Progression of coronary calcium and incident coronary heart disease events: MESA. J Am Coll Cardiol. 2013;61(12):1231-1239. doi:10.1016/j.jacc.2012.12.035.

[4] Budoff MJ, Young R, Burke G, et al. Ten-year association of coronary artery calcium with atherosclerotic cardiovascular disease events: the Multi-Ethnic Study of Atherosclerosis (MESA). Eur Heart J. 2018;39(25):2401-2408. doi:10.1093/eurheartj/ehy217.

[5] Blaha MJ, Cainzos-Achirica M, Greenland P, et al. Role of coronary artery calcium score of zero and other negative risk markers for cardiovascular disease: the Multi-Ethnic Study of Atherosclerosis (MESA). Circulation. 2016;133(9):849-858. doi:10.1161/CIRCULATIONAHA.115.018524.

[6] Sama C, et al. Non-calcified plaque in asymptomatic patients with zero coronary artery calcium score: a systematic review and meta-analysis. J Cardiovasc Comput Tomogr. 2024;18(1):43-49. doi:10.1016/j.jcct.2023.10.002.

[7] American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines. 2026 ACC/AHA/AACVPR/ABC/ACPM/ADA/AGS/APhA/ASPC/NLA/PCNA guideline on the management of dyslipidemia. Circulation. 2026;153(17):e1154-e1276. doi:10.1161/CIR.0000000000001423.

[8] Davis JR, et al. Utility of coronary artery calcium scoring in low-risk patients: the Multi-Ethnic Study of Atherosclerosis. Am J Prev Cardiol. 2025;24:101329. doi:10.1016/j.ajpc.2025.101329.

[9] Lee SE, Chang HJ, Sung JM, et al. Differential association between the progression of coronary artery calcium score and coronary plaque volume progression according to statins: the PARADIGM study. Eur Heart J Cardiovasc Imaging. 2019;20(11):1307-1314. doi:10.1093/ehjci/jez022.

[10] Messenger B, Li D, Nasir K, et al. Coronary calcium scans and radiation exposure in the Multi-Ethnic Study of Atherosclerosis. Int J Cardiovasc Imaging. 2016;32(3):525-529. doi:10.1007/s10554-015-0799-3.