CT Coronary Angiogram (CTCA)
This is a detailed, high-resolution scan that uses X-rays and a special dye (contrast material) to create 3D images of your heart and coronary arteries. It helps identify any blockages or narrowing in the arteries caused by fatty deposits (also called “furring”).
Calcium Score (CAC)
A calcium score measures the amount of calcium build-up in your heart’s arteries. Calcium is a marker of artery “furring” (atherosclerosis). The higher your score, the greater your risk of heart problems like a heart attack. A score of zero means no calcium deposits, while a higher score suggests a greater likelihood of artery blockages and future heart issues.
Benefits and Key Differences
- Calcium Score:
- A quick and simple way to estimate your risk of heart disease.
- It gives a number to indicate whether you’re at low, moderate, or high risk of future heart issues.
- It doesn’t show blockages directly or provide detailed images of your arteries.
- CTCA:
- Offers a more detailed and complete picture of your heart and arteries.
- Identifies specific blockages or narrowing and shows where they are.
- Helps determine whether blockages are in critical areas that might need closer attention.
Limitations of the Calcium Score
The coronary calcium test is most effective for individuals aged 45-70. While people outside this range can undergo the test, the results require cautious interpretation.
Limitations in Younger Individuals (<45):
- In younger people, plaques may not have had time to calcify, so the test can miss soft plaque.
- For instance, a 30-year-old with familial hypercholesterolemia could have soft, non-calcified plaques that result in a CAC score of 0, despite having a high risk of cardiac events.
- A low score in young individuals can give false reassurance, but a high score is a serious concern, indicating early plaque formation and increased future risk.
Limitations in Older Individuals (>70):
- Most people over 70 have some coronary artery calcification.
- A high score in this age group may not always indicate high risk unless it’s significantly elevated.
- Conversely, a low or zero score in older individuals can be very reassuring.
Why Choose One Over the Other?
A Calcium Score is a good starting point if you’re curious about your heart disease risk but don’t have symptoms. It’s like a snapshot of your risk level.
A CT Coronary Angiogram is more comprehensive and is typically recommended if:
- You have symptoms like chest pain or unexplained shortness of breath.
- Your calcium score suggests moderate to high risk, and more detail is needed.
- You’ve had inconclusive or negative results from stress tests but still have symptoms.
- Doctors suspect structural issues or anomalies in your coronary arteries.
In short, a calcium score helps predict risk, while a CT Coronary Angiogram provides detailed answers about your current heart health and any existing blockages. If you have symptoms or significant risk factors, a CT Coronary Angiogram offers more actionable insights.