A Coronary Artery Calcium (CAC) scan, also known as a calcium score test, is a non-invasive imaging test designed to detect calcified plaque in the coronary arteries. This test identifies the presence and extent of atherosclerosis, a condition where plaque builds up in the arteries, which can indicate a person’s risk for future cardiovascular events.
Understanding the Calcium Score Test
The calcium score test is a type of computed tomography (CT) scan that specifically images the heart. It detects calcium deposits in the walls of the coronary arteries, which serve as markers for atherosclerotic plaque. This waxy substance can narrow or block arteries over time.
While the test identifies calcium, which is part of hardened plaque, it does not directly measure soft plaque or current blockages. The presence of calcified plaque indicates past or ongoing damage to the arteries. The scan helps in estimating the overall burden of coronary artery disease, even before symptoms develop.
Interpreting Your Calcium Score
The result of a calcium score test is presented as an Agatston score, a numerical value that quantifies the amount of calcified plaque. A score of zero means no calcium is detected, indicating a very low likelihood of significant calcified plaque and a low risk of a heart attack in the near future.
Scores between 1 and 99 suggest minimal calcification and a low to mild risk of heart disease. A score ranging from 100 to 399 indicates moderate plaque deposits and a moderate to high risk for a heart attack. Scores of 400 or higher signify extensive calcification and a substantially increased risk of cardiovascular events.
A zero score does not completely eliminate heart disease risk, as other factors can contribute. However, it strongly suggests a low short-term risk. Conversely, higher scores highlight a greater burden of disease, prompting further discussion with a healthcare provider.
Assessing Test Reliability and Accuracy
The calcium score test is considered a reliable tool for predicting future cardiovascular events, such as heart attacks and strokes, particularly in individuals who do not yet show symptoms. Higher calcium scores are associated with an increased risk of coronary heart disease and all-cause mortality.
The test’s high predictive value stems from its ability to quantify the extent of atherosclerotic burden. However, the test has limitations; it cannot detect “soft” (non-calcified) plaque, which can also be unstable and lead to acute events.
The calcium score does not provide information about current blockages or blood flow, which requires different diagnostic tests. While highly reliable for risk stratification, it is not a diagnostic tool for immediate coronary events.
When a Calcium Score Test is Recommended
A calcium score test is typically recommended for asymptomatic individuals who have intermediate cardiovascular risk factors. These factors can include a family history of heart disease, elevated cholesterol, high blood pressure, diabetes, or a history of smoking. The test helps refine risk assessment beyond traditional risk calculators.
It is particularly useful for those aged 40 to 70 who are unsure about the need for preventive therapies like statins. For individuals with a low risk, the test may not provide additional useful information, and for those already at high risk or with established heart disease, it usually does not change management. The test helps clinicians and patients make informed decisions about personalized preventive strategies.
Navigating Your Health Journey After a Calcium Score Test
Receiving calcium score results necessitates a discussion with a healthcare provider to interpret them within your overall health context. A low score might reinforce current healthy habits, while a higher score serves as a prompt for more intensive preventive measures. The healthcare provider will consider the score alongside other risk factors, such as blood pressure, cholesterol levels, and family history.
Recommendations often include lifestyle modifications, such as adopting a heart-healthy diet, increasing physical activity, and quitting smoking. Depending on the score and individual risk profile, medication like statins to lower cholesterol or low-dose aspirin might be advised. In some cases, further diagnostic testing to assess blood flow may be recommended. The calcium score test is a tool to empower individuals and their doctors in developing a personalized plan for heart health.