From the Guidelines
A Coronary Artery Calcium (CAC) score is a crucial tool for refining risk assessment in individuals with intermediate predicted risk (≥7.5% to <20%) for cardiovascular disease, and can help guide preventive interventions such as statin therapy. The CAC score ranges from zero (no detectable plaque) to over 400 (extensive plaque), with a score of zero suggesting very low risk of heart attack in the next 5-10 years, and scores above 100 indicating moderate to high risk 1.
Key Points to Consider
- A CAC score of zero identifies individuals at lower risk of ASCVD events and death over a >10-year period, and may lead to postponing preventive interventions such as statins 1.
- A CAC score ≥100 Agatston units (AU) or ≥75th age/sex/race percentile can reclassify risk upward, indicating a higher risk of cardiovascular events 1.
- The CAC score is particularly useful for people with intermediate risk factors for heart disease, helping doctors make more informed decisions about preventive treatments 1.
- The test is quick, non-invasive, and exposes you to a relatively low radiation dose, making it a valuable tool for heart disease risk assessment.
Clinical Decision Making
- For individuals with a CAC score of 1 to 99, individual decision making is necessary because risk remains intermediate 1.
- A CAC score of 101 to 400 may indicate a high-risk population that could benefit from statin medication, especially if other risk factors are present 1.
- A CAC score >400 requires initiation of statin therapy, as it indicates a high risk of cardiovascular events 1.
Important Considerations
- The absence of coronary artery calcium does not rule out noncalcified plaque, and clinical judgment about risk should prevail 1.
- Coronary artery calcium measurement is not intended as a “screening” test for all, but rather may be used as a decision aid in select adults to facilitate the clinician–patient risk discussion 1.
From the Research
CAC Score Overview
- The Coronary Artery Calcium (CAC) score is a decision aid for further risk assessment and personalized management in the primary prevention of atherosclerotic cardiovascular disease 2.
- CAC scoring has emerged as a widely available, consistent, and reproducible means of assessing risk for major cardiovascular outcomes, especially useful in asymptomatic people for planning primary prevention interventions such as statins and aspirin 3.
CAC Score and Cardiovascular Risk
- A CAC score of zero may be used to de-risk individuals and inform the safe delay or avoidance of certain preventive therapies 2.
- CAC testing in asymptomatic populations is cost-effective across a broad range of baseline risk 3.
- Patients with a CAC score of zero remain at risk from noncalcified plaque components, and CTA-derived plaque characteristics can help identify patients at risk of acute coronary syndrome 4.
CAC Score in Symptomatic Patients
- The use of CAC testing in symptomatic patients has traditionally been limited due to concerns about its low specificity for obstructive CAD and ethnic variability in plaque composition and calcification patterns 5.
- CAC testing can be an effective gatekeeper to further testing in low-intermediate risk symptomatic patients with suspected coronary artery disease, particularly in ruling out significant coronary artery disease with a CAC score of zero 6.
- CAC scoring can play a vital role in symptomatic patients to detect coronary artery disease and establish the presence and severity of coronary atherosclerosis 5.