What is a cardiac calcium score (Coronary Artery Calcium score)?

From the Guidelines

A cardiac calcium score is a crucial medical test for assessing heart disease risk, and it is recommended for adults between 40-75 years with intermediate heart disease risk, family history of heart disease, or other risk factors like high cholesterol, diabetes, or smoking, as it helps determine appropriate preventive measures, such as lifestyle changes, medications like statins, or further cardiac testing, with a score of zero suggesting very low risk, 1-100 indicating mild disease, 101-400 moderate disease, and above 400 extensive disease, as supported by the most recent guidelines 1.

Key Points

• The cardiac calcium score test uses a specialized CT scan without contrast and takes about 10-15 minutes to complete, with radiation exposure of about 1 mSv, and costs between $100-400, though insurance coverage varies 2.
• The test measures the amount of calcium buildup in the coronary arteries, which can indicate heart disease risk, with higher scores indicating greater risk of future cardiac events, as shown in studies such as the Multi-Ethnic Study of Atherosclerosis (MESA) and the Coronary Artery Risk Development in Young Adults (CARDIA) study 2.
• A score of zero suggests very low risk, 1-100 indicates mild disease, 101-400 moderate disease, and above 400 extensive disease, with the presence and severity of coronary artery calcium being associated with the likelihood of benefit from statin therapy for ASCVD risk reduction, as recommended by the 2019 ACC/AHA guideline on the primary prevention of cardiovascular disease 3, 4.
• The test is typically recommended for adults between 40-75 years with intermediate heart disease risk, family history of heart disease, or other risk factors like high cholesterol, diabetes, or smoking, as it helps determine appropriate preventive measures, such as lifestyle changes, medications like statins, or further cardiac testing, with the goal of reducing morbidity, mortality, and improving quality of life 1, 5.

Benefits and Limitations

• The cardiac calcium score test has several benefits, including its ability to detect early coronary artery disease before symptoms develop, and its use as a decision aid in select adults to facilitate the clinician-patient risk discussion, as recommended by the major global coronary artery calcium guidelines 1.
• However, the test also has some limitations, including the potential for false negatives, and the need for careful interpretation of results in certain populations, such as younger adults or those with noncalcified plaque, as noted in the 2019 ACC/AHA guideline on the primary prevention of cardiovascular disease 3, 4.

From the Research

Cardiac Calcium Score Overview

• The cardiac calcium score, also known as the coronary artery calcium (CAC) score, is a measure of the amount of calcium in the coronary arteries, which is a marker of atherosclerotic plaque burden 6, 7, 8.
• A high CAC score is associated with an increased risk of coronary heart disease events, such as heart attacks and strokes 6, 9, 8.
• A CAC score of zero is associated with a very low risk of coronary heart disease events in the short to intermediate term, regardless of the number of traditional risk factors present 6, 7.

Clinical Use of Cardiac Calcium Score

• The CAC score can be used to identify individuals at increased risk for coronary heart disease events who may not be identified by traditional risk factors alone 6, 10, 8.
• The CAC score can inform personalized shared decision making and guide the use of preventive therapies, such as statins and aspirin 7, 9, 8.
• The CAC score can also be used to monitor the progression or regression of coronary artery disease over time 10, 8.

Risk Stratification and Prevention

• The CAC score can be used to stratify individuals into different risk categories, with those having a higher CAC score being at higher risk for coronary heart disease events 6, 9, 8.
• Combining the CAC score with a primary prevention strategy can reduce the progression of atherosclerotic plaque and lower the risk of coronary heart disease events in intermediate-risk individuals 9.
• The CAC score can also be used to identify individuals who may benefit from more intensive preventive strategies, such as those with a family history of premature coronary artery disease 9.