From the Guidelines
A coronary calcium score should be ordered for individuals at intermediate risk for cardiovascular disease, specifically those with a calculated 10-year atherosclerotic cardiovascular disease (ASCVD) risk of 5-20%, to guide preventive therapy decisions, as recommended by the 2019 ACC/AHA guideline 1. This test is most appropriate for asymptomatic adults aged 40-75 years where the decision to start statin therapy is uncertain. The test is particularly useful for patients with borderline risk factors such as family history of premature coronary disease, metabolic syndrome, or inflammatory conditions.
- A score of zero indicates very low risk, while scores above 100 suggest higher risk and may warrant more aggressive preventive measures including statin therapy, as supported by the 2018 AHA/ACC/AACVPR/AAPA/ABC/ACPM/ADA/AGS/APHa/ASPC/NLA/PCNA guideline 1.
- The test should not be ordered for patients who already have established coronary artery disease, are very low risk (young patients without risk factors), or are already definite candidates for statin therapy based on other risk factors.
- The calcium score helps visualize actual coronary atherosclerosis rather than just risk factors, providing a more personalized assessment of cardiovascular risk, as demonstrated by the MESA study 1 and the ACR Appropriateness Criteria 1.
- The radiation exposure is relatively low (approximately 1 mSv), and the test generally costs between $100-400, often not covered by insurance. Key considerations for ordering a coronary calcium score include:
- Intermediate risk (5-20% 10-year ASCVD risk)
- Borderline risk factors (family history, metabolic syndrome, inflammatory conditions)
- Uncertain decision to start statin therapy
- Asymptomatic adults aged 40-75 years
- Absence of established coronary artery disease or low risk (young patients without risk factors)
From the Research
Indications for Coronary Calcium Scoring
- Coronary artery calcium (CAC) scoring is recommended for individuals with intermediate 10-year atherosclerotic cardiovascular disease (ASCVD) risk 2
- CAC scoring is also recommended for selective populations with borderline ASCVD risk 2
- The test is useful in asymptomatic populations for planning primary prevention interventions such as statins and aspirin 3
- CAC scoring can be used to reclassify intermediate-risk individuals to a high risk, benefiting from preventive medication 4
Patient Selection
- Asymptomatic adults at intermediate risk (10%-20% 10-year-risk) may benefit from CAC scoring for cardiovascular risk assessment 5
- Low-to-intermediate risk (6%-10% 10-year-risk) individuals may also be considered for CAC scoring 5
- Diabetics over age 40 may benefit from CAC scoring for cardiovascular risk assessment 5
- Individuals with a 10-year ASCVD risk of 5% to 20% may benefit from CAC testing to guide shared decision making for statin therapy 6
Interpretation of Results
- A CAC score of 0 is the strongest negative predictive factor for cardiovascular disease (CVD) and can successfully de-risk a patient 2
- Higher CAC scores correlate with worse cardiovascular prognostic outcomes 2
- Elevated CACS (> 100 or > 75th percentile adjusted for age, sex, and ethnicity) can reclassify intermediate-risk individuals to a high risk 4
- A CAC score of 0 does not permanently reclassify to a lower cardiovascular risk, and periodic reassessment every 5 to 10 years remains necessary 4