What Does My Calcium Score Mean?
Coronary artery calcification (CAC) is pathognomonic (specifically characteristic) for coronary artery atherosclerosis (plaquing). The calcified component represents about 20% of the overall plaque.
Testing for the presence of coronary artery calcification by way of a non-contrast CT scan with Agatston score is appropriate for adults at intermediate risk as well as low risk individuals with a family history of premature heart disease. It allows for more personalized risk assessment, rather than extrapolating population data composed of risk factors to the individual.
CAC Agatston Scoring
0: None
1-10: Minimal
11-100: Mild
101-300: Moderate
> 300: Severe
> 1000: Very severe
The power of 0:
A score of 0 imparts a very low risk, with a 10 year event rate of 1.1-1.7% (Circ Cardiovasc Imaging 2012;5:467–73). CAC testing can therefore prevent the overtreatment in up to 50% of individuals where traditional risk calculators would have otherwise directed towards treatment with statin therapy. The time-frame for repeat scanning is unclear, but a repeat scan at 5 years seems to provide additional value, as those with 2 consecutive "0" scores have the lowest risk. However those with other high risk features, to include strong family history, may consider shorter intervals at 3-5 years.
Score 1-100:
In MESA, individuals with a calculated 10 year risk of a cardiovascular event between 5 and 7.5% (borderline for considering a statin) with any CAC score > 0 was associated with a risk > 7.5% (above the threshold for statin benefit). Therefore, the presence of any calcification in this group may justify treatment with lipid lowering therapy using a statin (J Am Coll Cardiol 2015;66:1657–68).
Score > 100:
This is considered to be a "coronary artery disease risk equivalent", meaning your 10-year risk of a future cardiovascular event is equivalent to someone who has already suffered an event (secondary prevention). Such individuals may benefit from lowering LDL-C