From the Guidelines
A Coronary Artery Calcium (CAC) score test is a non-invasive CT scan that measures the amount of calcified plaque in the coronary arteries, providing a numerical score ranging from 0 (no detectable plaque) to over 400 (extensive plaque), and is recommended for individuals at moderate risk of heart disease to assess their risk of future heart attacks or other cardiac events. The test is typically recommended for men over 45 and women over 55 with risk factors such as high blood pressure, high cholesterol, smoking, or family history of heart disease 1. The CAC score helps quantify coronary artery disease risk beyond traditional risk factors, with a higher score indicating a greater risk of future heart attacks or other cardiac events 1. Based on the results, your doctor may recommend lifestyle changes, medications like statins, or further cardiac testing 1. The test is usually not covered by insurance and may cost $100-$400 out of pocket. Some key points to consider when interpreting CAC scores include:
- CAC = 0 suggests low risk and may indicate that statin therapy is not necessary, unless other risk factors are present 1
- CAC = 1-99 favors statin therapy, especially in individuals over 55 years of age 1
- CAC = 100+ and/or ≥75th percentile requires initiation of statin therapy 1 The CAC score is a useful tool for refining risk assessment and guiding treatment decisions in individuals at moderate risk of heart disease, and can help identify those who may benefit from more aggressive preventive measures 1.
From the Research
Definition and Purpose of Coronary Artery Calcium (CAC) Score Test
- The CAC score test is a non-invasive quantitation of coronary artery calcification using computed tomography (CT) 2.
- It is a marker of atherosclerotic plaque burden and an independent predictor of future myocardial infarction and mortality 2, 3.
- The test provides incremental risk information beyond traditional risk calculators, such as the Framingham Risk Score 2, 3, 4, 5.
Interpretation of CAC Scores
- A zero score confers a very low risk of death, <1% at 10 years 2.
- Scores between 1-100 indicate low risk, <10% 2.
- Scores between 101-400 indicate intermediate risk, 10-20% 2.
- Scores >400 indicate high risk, >20% 2.
- The score can be used to refine risk estimates in the intermediate range of 7.5%-20% over 10 years 4.
Clinical Use and Recommendations
- The CAC score test can be used for risk stratification in primary prevention of cardiovascular events 2, 3, 4, 5.
- It is recommended for patients with intermediate risk, as it can help identify increased risk and motivate effective behavioral changes 3.
- The test can be used to initiate or intensify appropriate treatment strategies to slow the progression of atherosclerotic vascular disease 3.
- Repeat CAC testing is not currently recommended, except in patients with a CAC of 0, where a repeat test may be considered in 5 years 2.