From the Guidelines
Coronary calcium score testing is a valuable tool for assessing cardiovascular risk, particularly in patients with intermediate risk where traditional risk calculators may not provide clear guidance, as supported by the most recent study from 2023 1. This non-invasive CT scan measures the amount of calcium in the coronary arteries, with higher scores indicating greater plaque burden and increased risk of future cardiovascular events. A score of zero suggests very low risk, while scores above 100 indicate moderate risk and those above 300 signify high risk. The test is most beneficial for individuals aged 40-75 with intermediate risk factors such as family history of heart disease, borderline hypertension, or cholesterol abnormalities. It's particularly useful when there's uncertainty about whether to start preventive therapies like statins. The biological basis for this test is that calcium deposition occurs as part of the atherosclerotic process, serving as a marker for coronary artery disease even before symptoms develop. However, the test involves radiation exposure (though minimal) and doesn't detect non-calcified plaque, which can still cause heart attacks. Results should be interpreted in the context of other risk factors and used to guide preventive strategies including lifestyle modifications and medication decisions, as recommended by the 2019 ACC/AHA guideline on the primary prevention of cardiovascular disease 1. Some key points to consider when interpreting coronary calcium scores include:
- A score of zero is associated with very low risk of cardiovascular events, and statin therapy may be of limited value in these individuals 1.
- Scores above 100 indicate moderate risk, and those above 300 signify high risk, making them suitable targets for stringent lifestyle recommendations and evidence-based therapeutic agents to reduce cardiovascular risk 1.
- The test is most beneficial for individuals with intermediate risk factors, and its results should be used to guide preventive strategies, including lifestyle modifications and medication decisions, as supported by studies such as MESA and the Prospective Army Coronary Calcium study 1. Overall, coronary calcium score testing is a useful tool for assessing cardiovascular risk and guiding preventive therapies, and its results should be interpreted in the context of other risk factors and used to inform clinical decision-making, as recommended by the most recent guidelines and studies 1.
From the Research
Role of Coronary Calcium Score Testing
The role of coronary calcium score testing in assessing cardiovascular risk is a significant one, as it helps to identify individuals at high risk of cardiovascular events.
- Coronary artery calcium (CAC) testing is not recommended for universal screening, but rather for selected patients who are at intermediate or borderline risk of atherosclerotic cardiovascular disease (ASCVD) 2.
- The test can be used as a sequential decision aid after initial quantitative risk assessment and consideration of individual patient risk-enhancing factors, such as strong family history of premature ASCVD or chronic kidney disease 2.
- CAC testing can meaningfully reclassify risk and support improved targeting of drug therapy to patients most likely to benefit, particularly in those at intermediate risk 2, 3.
Assessment of Cardiovascular Risk
The assessment of cardiovascular risk using CAC scoring is based on the presence and extent of coronary artery calcium.
- A CAC score of 0 is associated with a low risk of cardiovascular events, while a score greater than 0 is associated with an increased risk of major adverse cardiovascular and cerebrovascular events (MACE) 4.
- The use of CAC scoring is associated with significant improvements in the reclassification and discrimination of incident ASCVD, particularly when used in conjunction with risk-enhancing factor assessment 5.
- CAC scoring can be used to guide statin therapy allocation according to risk-enhancing factors, and can help to identify individuals who may benefit from primary prevention medications such as statins or aspirin 2, 5.
Clinical Applications
The clinical applications of CAC scoring are varied, and include:
- Primary prevention of ASCVD: CAC scoring can be used to identify individuals at high risk of ASCVD, and to guide the allocation of statin therapy 2, 5.
- Risk assessment: CAC scoring can be used to assess cardiovascular risk, particularly in individuals with intermediate or borderline risk of ASCVD 2, 3.
- Shared decision making: CAC scoring can be used to inform shared decision making between clinicians and patients, particularly in cases where the decision to initiate or intensify statin therapy is uncertain 3.