Understanding the Calcium Score Test
A coronary artery calcium (CAC) scan, also known as a heart scan, is a non-invasive imaging test using computed tomography (CT) to assess heart health. This scan specifically identifies and quantifies calcified plaque within the coronary arteries, the blood vessels supplying oxygen-rich blood to the heart. The presence of calcium indicates atherosclerosis, a condition where fatty substances and other materials build up, potentially narrowing or blocking blood flow over time.
The procedure is quick, typically taking 10-15 minutes. It does not require any injection of contrast material. During the scan, electrodes are placed on the chest to monitor heart rhythm, and the patient lies on a movable table that slides into the CT scanner. Patients might be asked to hold their breath briefly to ensure clear images.
The calcium score test aims to detect subclinical atherosclerosis, identifying arterial disease before symptoms appear. This early detection is valuable because atherosclerosis often progresses silently for years before causing issues like chest pain or heart attacks, providing insights into an individual’s heart disease burden.
What Calcium Scores Reveal About Heart Health
The results of a calcium score test are presented as an Agatston score, which quantifies calcified plaque in the coronary arteries. A score of zero signifies no detectable calcium, indicating minimal or no atherosclerotic plaque burden and a low likelihood of a future heart attack.
Scores between 1 and 100 suggest a small to mild amount of plaque, indicating early coronary artery disease. While some plaque is present, the immediate risk of a cardiac event is relatively low. Individuals with these scores often benefit from lifestyle modifications to prevent further disease progression.
Scores above 100, particularly those exceeding 400, signify moderate to extensive calcified plaque. A score between 100 and 300 suggests moderate plaque and a high risk of heart attack or other heart disease events over the next three to five years. A score over 400 indicates a substantial atherosclerotic burden. Higher scores correlate with greater atherosclerosis and increased risk of events like heart attack or stroke.
Factors Affecting Test Reliability
While a coronary artery calcium (CAC) scan strongly predicts future cardiovascular events, its reliability is influenced by several factors. A high calcium score accurately indicates atherosclerotic plaque and elevated heart disease risk. However, a zero score, while associated with a very low risk of cardiac events in the next two to five years, does not eliminate the possibility of future issues, especially for younger individuals or those with specific plaque types.
The test primarily detects calcified plaque, a stable, later stage of atherosclerosis. It does not directly visualize “soft” or non-calcified plaque, which can rupture and cause acute events. Thus, a person with a zero score could still have non-calcified plaque posing a risk, especially with significant traditional risk factors.
Age and gender also play a role in interpreting results; younger individuals, particularly women, may have lower calcium scores despite being at risk. Non-atherosclerotic calcification can sometimes occur, potentially leading to a false positive for heart disease. Conversely, very early atherosclerosis might not yet show calcification, which could be considered a false negative for nascent disease. The calcium score is valuable, but functions best as part of a comprehensive risk assessment rather than a standalone diagnostic tool.
How Calcium Score Results Guide Heart Health Management
Calcium score results are integrated with other patient data to create a personalized heart health management plan. Healthcare providers consider the calcium score alongside traditional risk factors such as cholesterol levels, blood pressure, family history of heart disease, and lifestyle choices like smoking and diet. This comprehensive approach allows for a more precise assessment of an individual’s overall cardiovascular risk.
For individuals with elevated calcium scores, even in the absence of symptoms, the results can prompt more aggressive preventive measures. These may include intensified lifestyle modifications, such as dietary changes, increased physical activity, and smoking cessation. Depending on the score and other risk factors, medication, such as statins to lower cholesterol or blood pressure-lowering drugs, might be recommended to mitigate future event risk.
The test is particularly useful for asymptomatic individuals who are considered to be at intermediate risk for cardiovascular disease based on standard risk calculators. For these individuals, the calcium score can help reclassify their risk, either indicating a higher need for intervention or providing reassurance of a lower risk. This allows for tailored prevention strategies, potentially avoiding unnecessary treatments for those with low scores or guiding more focused interventions for those found to be at higher risk.