From the Guidelines
CT cardiac calcium scans are a valuable diagnostic tool for assessing cardiovascular risk, particularly in asymptomatic patients at intermediate risk for coronary artery disease, as they provide a quantifiable measure of calcium deposits in coronary arteries, which is predictive of future coronary heart disease events. The use of CT coronary calcium scans has been extensively studied, and the evidence suggests that they are a useful tool for risk stratification 1. The Agatston score, which is derived from the scan, has been shown to be predictive of coronary heart disease, with higher scores indicating a greater risk of events 1. For example, a study of 6,814 participants found that a CAC score >100 was predictive of coronary heart disease, with an event rate of 2.4% over a period of 10.4 years 1. Another study of 14,169 low-risk patients with a family history of CAD found that a calcium score of >100 had a 2.2 times higher risk for all-cause mortality, 4.3 times higher cardiovascular specific mortality, and 10.4 times higher risk of coronary heart disease, than patients with a zero calcium score 1.
The benefits of CT cardiac calcium scans include their non-invasive nature, quick scan time, and relatively low radiation exposure. They are particularly useful for asymptomatic adults aged 40-75 with risk factors but no known coronary artery disease. However, the scan has some limitations, including the inability to detect soft plaque and the potential for inaccurate results in patients with stents or pacemakers. Despite these limitations, the evidence suggests that cardiac calcium scoring provides valuable information that can guide personalized preventive strategies and potentially save lives through early intervention 1. Some of the key findings from the studies include:
- A CAC score >100 is predictive of coronary heart disease 1
- The presence of any CAC (>0) is associated with an increased risk of major adverse cardiovascular events (MACE) 1
- The relative adjusted subhazard ratio for CAC 1 to 100,101 to 400, and >400 was 2.2,3.8, and 5.9 for myocardial infarction 1
- The scan is quick, non-invasive, and exposes patients to relatively low radiation 1
Overall, the evidence suggests that CT cardiac calcium scans are a valuable tool for assessing cardiovascular risk and guiding preventive strategies, particularly in asymptomatic patients at intermediate risk for coronary artery disease 1.
From the Research
Value of CT Cardiac Calcium Scans
- CT cardiac calcium scans, also known as coronary artery calcium (CAC) scans, have been shown to be a valuable tool in cardiovascular risk assessment and stratification 2, 3, 4, 5, 6.
- CAC scans can help identify individuals at high risk of cardiovascular events, such as heart attacks and strokes, and can also help guide treatment decisions, such as the use of statins and antiplatelet therapies 2, 4, 6.
- The use of CAC scans has been shown to improve cardiovascular risk prediction and can be used to monitor individual response to anti-atherosclerotic therapies 2, 3, 5.
- CAC scans are a cost-effective way to assess cardiovascular risk, especially in asymptomatic individuals, and can help identify patients who may benefit from early intervention and prevention strategies 4, 5, 6.
Clinical Applications of CT Cardiac Calcium Scans
- CAC scans can be used to guide lipid-lowering and antiplatelet therapy, and can help identify patients with a favorable risk/benefit relationship for these therapies 2, 4.
- CAC scans can also be used to monitor plaque burden and plaque phenotyping, which can help guide anti-atherosclerotic therapies and monitor individual response to these treatments 2, 3.
- The CAC Consortium, a multicenter, retrospective, real-world cohort study, has shown that CAC can effectively stratify cardiovascular risk across ethnicities, irrespective of age, sex, and risk factor burden 6.
Limitations and Future Directions
- While CAC scans have been shown to be a valuable tool in cardiovascular risk assessment, there are still limitations to their use, including the need for further technical advances in CT image acquisition and cost-effectiveness analysis 3, 5.
- Future studies are needed to further establish the clinical utility of CAC scans and to explore new applications, such as the use of CAC in select young patients and in low-risk patients with a family history 6.