From the Guidelines
The CT calcium score should be repeated every 5 years for individuals with a zero calcium score and low cardiovascular risk, every 3-5 years for those with a positive calcium score (1-99), and every 2-3 years for those with moderate scores (100-399), while individuals with high scores (400+) typically don't need repeat testing.
Key Considerations
- The frequency of repeating a CT calcium score test depends on individual risk factors and initial results, as suggested by the major global coronary artery calcium guidelines 1.
- For low-risk individuals or those with CAC = 0, the ACC/AHA and CSANZ recommend that CAC screening may be repeated in 5 to 10 years, while the ESC guidelines recommend that for CAC = 0, repeat screening should not be performed <5 years from the initial scan 1.
- The NLA recommends that the timing for repeat CAC score depends on a patient’s baseline estimated ASCVD risk, varying from 3 to 7 years, with specific intervals for low-risk, borderline- to intermediate-risk, and high-risk or diabetes patients 1.
- Rapid progression (increase >15% per year) may indicate higher cardiovascular risk requiring more intensive management, as seen in the MESA study and the Heinz Nixdorf Recall Study 1.
Adjusting Intervals Based on Risk Factors
- Personal risk factors such as family history, diabetes, hypertension, or smoking status should be taken into account when determining the appropriate interval for repeating the CT calcium score test.
- Diabetic patients or those with CAC 101 to 400 should undergo repeat CAC at 3 years, according to the CSANZ guidelines 1.
- Individuals with high CAC (>400) may not require repeat CAC screening, as they are often symptomatic and already vigorously treated, but functional testing may be considered on an individualized basis 1.
Importance of Discussing with a Healthcare Provider
- It is essential to discuss with a healthcare provider to determine the appropriate interval based on an individual's specific situation, as unnecessary repeated testing increases radiation exposure without clinical benefit.
- The purpose of repeating the test is to monitor progression of coronary artery calcification, which can help guide preventive strategies and improve patient outcomes.
From the Research
CT Calcium Score Repeat Frequency
The frequency of repeating a CT calcium score is not explicitly stated in the provided studies. However, the studies suggest that coronary artery calcium (CAC) scoring is a useful tool for assessing cardiovascular risk and guiding preventive therapy.
- The studies 2, 3, 4, 5 discuss the use of CAC scoring for cardiovascular risk stratification and its potential to improve the yield of statin therapy in primary prevention.
- Study 4 analyzed the relationship between statin benefit groups and CAC score in an asymptomatic Korean population, but did not provide guidance on the frequency of repeating the test.
- Study 5 reviewed the current evidence on the use of CACS and coronary CT angiography for guiding lipid-lowering and antiplatelet therapy, but did not address the frequency of repeating the test.
- Study 6 explored CTA-derived coronary artery plaque characteristics in symptomatic patients with CAC score of zero who experienced subsequent acute coronary syndrome, but did not provide information on the frequency of repeating the test.
Factors Influencing Repeat Frequency
While the studies do not provide direct guidance on the frequency of repeating a CT calcium score, they suggest that the following factors may influence the decision to repeat the test:
- Changes in cardiovascular risk factors, such as age, gender, and fasting blood glucose 4
- Changes in statin therapy or antiplatelet therapy 3, 5
- Presence of noncalcified plaque components 6
Limitations
The provided studies do not provide sufficient evidence to determine the optimal frequency for repeating a CT calcium score. Further research is needed to establish guidelines for repeat testing.