From the Guidelines
A calcium score of zero indicates a very low risk of coronary artery disease and future cardiac events, with less than a 1% chance of having significant coronary artery narrowing and a low risk of experiencing a heart attack in the next 5-10 years. This is excellent news, as it suggests that the individual has a low burden of atherosclerotic cardiovascular disease (ASCVD) [ 1 ]. According to the 2019 ACC/AHA guideline on the primary prevention of cardiovascular disease, a coronary artery calcium score of zero can be useful in identifying individuals who may not benefit from statin therapy, particularly those with low to intermediate risk [ 1 ].
Key Points to Consider
- A zero calcium score does not completely rule out the presence of early non-calcified plaque or guarantee that the individual will never develop heart disease in the future [ 1 ].
- It is still important to maintain heart-healthy habits, including regular exercise, a balanced diet low in saturated fats, not smoking, managing stress, and attending regular check-ups, especially if there are other cardiovascular risk factors present [ 1 ].
- The calcium score test uses CT scanning to detect calcium deposits in arterial plaque, which only appear in more advanced stages of atherosclerosis [ 1 ].
- A coronary artery calcium score of zero can help reclassify individuals as low risk, potentially sparing them from unnecessary statin therapy and its associated costs and side effects [ 1 ].
Implications for Clinical Practice
- A zero calcium score can inform patient-clinician discussions about treatment options and associated risks [ 1 ].
- Coronary artery calcium scoring can be a useful tool for personalizing individual therapy and assessing the potential value of statin therapy [ 1 ].
- The decision to use medication, especially in intermediate-risk patients, may be influenced by the presence of risk-enhancing factors and the results of the coronary artery calcium score [ 1 ].
From the Research
Calcium Score of Zero
A calcium score of zero indicates that no calcium deposits were found in the coronary arteries. This score is often referred to as the "power of zero" because it can be used to de-risk individuals and inform the safe delay or avoidance of certain preventive therapies, such as statins 2.
Prognostic Value
The prognostic value of a calcium score of zero is significant, as it is associated with a low risk of cardiovascular events. Studies have shown that individuals with a calcium score of zero have a lower risk of major adverse cardiovascular and cerebrovascular events (MACE) compared to those with a calcium score greater than zero 3, 4. Additionally, a calcium score of zero is associated with a lower risk of all-cause mortality and cardiovascular mortality 3, 4.
Comparison to Other Risk Markers
A calcium score of zero is considered one of the strongest negative risk markers for cardiovascular disease. It has been shown to be more effective than other risk markers, such as carotid intima-media thickness and high-sensitivity C-reactive protein, in identifying individuals at low risk of cardiovascular events 4.
Limitations
While a calcium score of zero is associated with a low risk of cardiovascular events, it is not a guarantee that an individual will not experience a cardiovascular event. Some studies have shown that individuals with a calcium score of zero can still have non-calcified plaques and experience cardiovascular events 5, 6. Therefore, a calcium score of zero should be considered in the context of other risk factors and medical history.
Clinical Implications
A calcium score of zero can be used to inform clinical decision-making, such as the use of preventive therapies and the frequency of follow-up appointments. Individuals with a calcium score of zero may be able to safely delay or avoid certain preventive therapies, such as statins, and may require less frequent follow-up appointments 2. However, it is essential to consider other risk factors and medical history when making clinical decisions.