From the Guidelines
A coronary artery calcium (CAC) score should be obtained in selected adults with uncertain risk decision, particularly those aged 40-75 with intermediate risk factors, to guide statin therapy initiation. This recommendation is based on the most recent guidelines from major global coronary artery calcium studies 1. The CAC score is a valuable tool in assessing atherosclerotic cardiovascular disease (ASCVD) risk and can help inform treatment decisions.
When considering a CAC score, the following key points should be taken into account:
- A CAC score of zero suggests low risk and may indicate that statin therapy can be withheld, unless other high-risk conditions are present, such as diabetes, family history of premature CHD, or cigarette smoking 1.
- A CAC score of 1-99 favors statin therapy, especially in individuals over 55 years of age 1.
- A CAC score of 100 or higher, or in the 75th percentile or higher, indicates a higher risk and suggests initiation of statin therapy 1.
It is essential to note that the CAC score should be used in conjunction with other risk factors and clinical judgment to guide treatment decisions. The test is most beneficial when the results might change the treatment plan, such as deciding whether to start statin medications. Before scheduling a CAC score test, it is crucial to consult with a doctor to determine if this test is appropriate for the specific situation and to properly assess cardiovascular risk and interpret the results in the context of overall health.
From the Research
Coronary Artery Calcium Scoring
The decision to obtain a coronary artery calcium (CAC) score is based on several factors, including the patient's risk profile and the potential to change therapy based on the test result 2.
- Patient Groups to Consider: CAC scoring can be considered for patients who are not classified as high or low risk, particularly those with an intermediate risk profile 2, 3, 4.
- Intermediate Risk Patients: Patients with an intermediate risk profile (10-20% ten-year risk) may benefit from CAC scoring to refine their risk assessment and guide preventive therapy 3, 4, 5.
- CAC Score Interpretation: A CAC score of 0 indicates a very low risk of death (<1% at 10 years), while higher scores indicate increasing levels of risk 2.
- Management Recommendations: Patients with moderately high or high risk based on CAC score may benefit from preventative medical therapy, such as aspirin and statins 2, 5.
- Repeat CAC Testing: Repeat CAC testing is not currently recommended for patients with a positive calcium score, except in cases where there is a significant increase in CAC (>15% or >100 units per year) 2, 3.
Cost-Effectiveness of CAC Scoring
The cost-effectiveness of CAC scoring in primary prevention is still being debated, with some studies suggesting that it may be cost-effective in certain scenarios, particularly when statin therapy is costly or has significant quality of life implications 5.
- Cost-Effectiveness Analysis: A cost-effectiveness analysis of CAC scoring and statin therapy found that measuring CAC and targeting statin treatment to patients with CAC>0 could be cost-effective in certain scenarios, particularly when statin assumptions are less favorable 5.
- CAC Testing in Intermediate Risk Patients: CAC testing in intermediate risk patients can be cost-effective, but only if statins are costly or significantly affect quality of life 5.
Clinical Use of CAC Scoring
CAC scoring has been shown to be a useful predictor of coronary artery disease and can be used to guide primary prevention interventions 4, 6.
- Predictive Ability: CAC scoring has been shown to have a high sensitivity for the presence of coronary artery disease and can predict future cardiovascular risk in asymptomatic patients 4.
- Incremental Utility: CAC scoring has been shown to have incremental utility over traditional risk factors, such as the pooled cohort equation, particularly in intermediate risk patients 6.