From the Guidelines
Calcium scoring for chronic coronary artery disease is performed using a non-contrast computed tomography (CT) scan of the heart, which detects and quantifies calcium deposits in the coronary arteries, indicating the presence of atherosclerotic plaque. The procedure involves the patient lying on a CT scanner table while the machine takes multiple X-ray images of the heart. These images are then analyzed using specialized software that calculates the Agatston score, which measures the total amount of calcium in the coronary arteries 1. Scores range from zero (no detectable calcium) to over 400 (extensive calcification), with higher scores indicating greater plaque burden and increased risk of future cardiac events.
Key Points to Consider
- The scan typically takes only about 10-15 minutes to complete and requires no special preparation other than avoiding caffeine before the test.
- The calcium score provides valuable prognostic information beyond traditional risk factors and can help determine the appropriate intensity of preventive measures such as statin therapy 1.
- A coronary artery calcium score of zero identifies individuals at lower risk of ASCVD events and death over a >10-year period, who appear to derive little or no benefit from statins for ASCVD risk reduction 1.
- The presence and severity of coronary artery calcium have been shown to be associated with the likelihood of benefit from statin therapy for ASCVD risk reduction 1.
Clinical Application
The test is particularly useful for asymptomatic patients with intermediate cardiovascular risk to help guide preventive therapy decisions. The calcium score can reclassify risk upward or downward in a significant proportion of individuals, providing confidence that borderline- or intermediate-risk patients with elevated coronary artery calcium will have event rates that clearly exceed benefit thresholds, and those with coronary artery calcium scores of zero will have event rates <7.5% 1.
Recent Evidence
Recent studies suggest that prolonged statin therapy may have procalcific effects on coronary atheromas and can increase CAC; thus, follow-up CACS has limited value in patients with baseline CACS > 400, who are already at high risk 1. However, the most recent CACS result, rather than CAC progression, should be used for risk assessment. Longitudinal follow-up is meaningful at 3-to-5-year intervals, and follow-up scans could be useful in patients with initial CACS = 0 who have diabetes or multiple cardiovascular risk factors 1.
From the Research
Calcium Scoring Procedure
Calcium scoring is a non-invasive test used to detect and measure the amount of calcium in the coronary arteries, which can indicate the presence and severity of coronary artery disease (CAD) [ 2, 3 ]. The test is typically performed using a computed tomography (CT) scanner.
Indications for Calcium Scoring
Calcium scoring is commonly used in patients with suspected CAD, particularly those with chest pain or dyspnea [ 2 ]. It can also be used to assess cardiovascular risk in asymptomatic individuals [ 4 ].
Interpretation of Calcium Scoring Results
The results of calcium scoring are typically reported as a score, which can range from 0 to over 1000 [ 5 ]. A score of 0 indicates the absence of calcium in the coronary arteries, while higher scores indicate increasing amounts of calcium. The score can be used to estimate the risk of CAD and guide further testing or treatment [ 3 ].
Limitations of Calcium Scoring
While calcium scoring is a useful tool for detecting CAD, it has some limitations. For example, it may not detect non-calcified plaques, and high amounts of calcium can make it difficult to interpret the results of coronary CT angiography [ 6 ]. Additionally, calcium scoring may not be suitable for all patients, particularly those with very extensive calcium deposits [ 6 ].
Key Findings
- Calcium scoring can be used to detect and measure the amount of calcium in the coronary arteries [ 2 ].
- A calcium score of 0 can rule out obstructive CAD in symptomatic patients [ 3 ].
- Calcium scoring can reclassify cardiovascular risk in patients undergoing coronary CT angiography [ 5 ].
- High amounts of calcium can pose challenges in interpretation of coronary CT angiography [ 6 ].
Calcium Scoring in Clinical Practice
- Calcium scoring is a useful tool for detecting CAD and guiding further testing or treatment [ 2, 3 ].
- It can be used in combination with other tests, such as coronary CT angiography, to provide a more comprehensive assessment of cardiovascular risk [ 5 ].
- Clinicians should consider the limitations of calcium scoring when interpreting the results and making treatment decisions [ 6 ].
Some key points to consider when performing calcium scoring for chronic coronary artery disease include:
- The test is non-invasive and relatively quick [ 2 ].
- It can be used to detect and measure the amount of calcium in the coronary arteries [ 2 ].
- The results can be used to estimate the risk of CAD and guide further testing or treatment [ 3 ].
- High amounts of calcium can pose challenges in interpretation of coronary CT angiography [ 6 ].