Calcium Score (CAC) by Age 

March 17th, 2025

Coronary artery calcium (CAC) scoring helps in assessing patients with cardiovascular risk, particularly in those who are asymptomatic. The calcium score, derived from a computed tomography (CT) scan, quantifies calcified plaque in the coronary arteries, providing clinicians with insight into the patient’s risk for coronary artery disease (CAD) and cardiovascular events. Understanding how calcium scores vary by age is critical in optimizing risk stratification and guiding preventive therapies.

Let’s explore the significance of CAC scoring, its interpretation by age group, clinical implications, and management strategies based on score assessment. We’ll also discuss emerging research on CAC progression, the role of adjunctive imaging techniques, and evolving risk stratification paradigms.

1. Pathophysiology of coronary calcium deposition

Coronary artery calcification occurs as part of the atherosclerotic process. Over time, lipid-laden plaques undergo dystrophic calcification, a process mediated by inflammatory cytokines, vascular smooth muscle cell differentiation, and oxidative stress.

While calcification is typically associated with stable plaques, a high CAC score correlates with a greater burden of atherosclerosis and increased cardiovascular risk.

Key factors contributing to coronary calcification

• Age-related vascular changes

• Hypertension and endothelial dysfunction

• Dyslipidemia and chronic inflammation

• Diabetes and insulin resistance

• Genetic predisposition to arterial calcification

• Smoking and chronic oxidative stress

• Chronic kidney disease and calcium-phosphorus metabolism disorders

CAC and plaque stability

Recent studies suggest that calcified plaques may be more stable compared to non-calcified plaques, which are prone to rupture and acute cardiovascular events. However, a high overall CAC score still signifies an extensive atherosclerotic burden, necessitating aggressive management.

2. Calcium score measurement and interpretation

CAC scoring is performed using non-contrast cardiac CT and quantified using the Agatston scoring method. The total calcium score is stratified into these risk categories.

Limitations of CAC scoring

While CAC scoring is a useful risk stratification tool, it doesn’t provide information on non-calcified plaques, which can still pose significant cardiovascular risk. Complementary imaging modalities, such as coronary CT angiography (CCTA), may provide additional insights into plaque composition.

3. Calcium score by age

CAC scores vary significantly with age, as coronary calcification is more common in older individuals. Below are the typical distributions by age group:

Ages 20–39

• Most individuals have a CAC score of zero.

• Any detectable calcium in this age group is concerning and suggests early atherosclerosis.

• Patients with a nonzero CAC score should undergo aggressive risk factor modification.

Ages 40–49

• A CAC score of zero remains common in low-risk individuals, but some calcifications may begin to appear in those with cardiovascular risk factors.

• A score >100 in this group signifies significantly elevated cardiovascular risk.

Ages 50–59

• The prevalence of coronary calcium increases significantly.

• A CAC score of 1–100 is common, while scores >400 indicate a high likelihood of coronary artery disease.

Age 60 and older

• Most individuals in this group will have some degree of coronary calcification.

• CAC scores >400 are frequently observed, necessitating aggressive risk reduction and further cardiac evaluation.

4. Clinical implications of CAC scoring

Low CAC scores (0–10)

• This suggests a very low risk of cardiovascular events.

• Emphasis should remain on lifestyle optimization and routine monitoring.

Intermediate CAC scores (11–100)

• This indicates mild atherosclerosis with a need for individualized risk assessment.

• Lifestyle changes, lipid-lowering therapy, and blood pressure management are recommended.

High CAC scores (101–400)

• This signifies moderate to severe atherosclerosis and a high cardiovascular risk.

• Statin therapy is strongly recommended, along with blood pressure control and lifestyle modifications.

Very high CAC scores (>400)

• This suggests extensive coronary artery disease and a higher risk of adverse cardiovascular events.

• This requires aggressive medical therapy and further cardiac evaluation, including stress testing and coronary angiography.

5. Management strategies based on CAC score

Lifestyle and preventive measures

• Diet: Encourage adherence to a heart-healthy diet such as the Mediterranean or Dietary Approaches to Stop Hypertension (DASH) diet.

• Exercise: Engage in regular physical activity (moderate to vigorous) for at least 150 minutes per week.

• Smoking cessation: This is essential for all patients to slow the progression of atherosclerosis.

• Blood pressure control: Help patients maintain optimal blood pressure (BP) to reduce further vascular injury.

Pharmacologic interventions

• Statins: This is a first-line therapy for individuals with a CAC score >100 or multiple risk factors.

• Aspirin: This can be considered for patients with high CAC scores and additional cardiovascular risk factors.

• Blood pressure control: The target BP is <130/80 mmHg in high-risk individuals.

• PCSK9 Inhibitors: This may be considered in high-risk patients with persistent LDL elevation despite statin therapy.

6. Special considerations

Gender differences

• Men tend to develop coronary calcification earlier than women.

• Women with a high CAC score have a disproportionately higher cardiovascular risk compared to men with the same score.

Diabetes and CAC score

• Diabetic patients with a CAC score >100 are considered at high cardiovascular risk, warranting intensive management.

• A CAC score of zero in diabetic patients may help guide decisions against unnecessary statin therapy.

Ethnicity and CAC prevalence

• CAC prevalence and severity vary among racial and ethnic groups, with African Americans having lower calcium scores than white individuals despite similar risk factors.

• South Asian Americans tend to have higher CAC scores at younger ages, correlating with their increased cardiovascular risk.

7. Future directions and research

• Advanced imaging techniques: Explore the role of artificial intelligence in CAC scoring.

• Biomarkers and genetics: Identify novel markers to refine cardiovascular risk prediction.

• Personalized therapy: Use CAC scores in precision medicine to tailor interventions.

• Longitudinal studies: Investigate CAC progression over time and its implications for cardiovascular outcomes.

Calcium scoring is a powerful tool for refining cardiovascular risk assessment, particularly when used in conjunction with traditional risk factors. Understanding how CAC scores vary by age allows clinicians to guide appropriate preventive measures, ensuring early intervention in high-risk individuals. As research progresses, CAC scoring will continue to evolve, enhancing our ability to predict and prevent coronary artery disease effectively.