Today in Cardiology Report, we discussed the case of a middle-aged woman with history of provoked DVT s/p IVC filter placement, not on anticoagulation, who presented with subacute onset of pleuritic chest pain and shortness of breath of unclear etiology. See below for pearls on “coronary calcium score.”
Coronary Calcium Score
- What is it?
- Electron beam or multidetector row CT scan is used to generate serial thin section tomograms from the aorta à apex of the heart, to generate a score that estimates the amount of calcium plaque in your coronary arteries
- When should you order?
- Generally, should be used for cardiovascular risk assessment in asymptomatic adults at intermediate risk (10-20% 10-year risk by Framingham risk score), if the result is expected to lead to management changes.
- Should not be used in patients with low (<10% risk) or high (>20%) risk.
- Serial score calculations to monitor progression or regression of coronary artery disease is not recommended.
- JAMA 2010 article (PMID:20424251): addition of coronary artery calcium score to a prediction model based on traditional risk factors significantly improved the classification of risk and placed more individuals in most extreme risk categories
- What does it predict?
- In general, it is a better marker for the extent of coronary atherosclerosis rather than severity of stenosis
- Note, it does NOT provide functional information (such as impaired blood flow resulting in ischemia)
- The following scoring cut-offs have been proposed:
- Score of 0 – no identifiable coronary artery disease
- Score of 1- 99 – mild disease
- Score of 100 – 399 – moderate disease
- > 400 – severe disease
- Test Characteristics
- Presence of coronary artery calcium is highly sensitive for presence of > 50% stenosis, but only moderately specific (especially in older patients). In one study, sensitivity and specificity were 91 and 49%, respectively
- With higher calcium scores, sensitivity decreases, but specificity increases
- Absence of coronary artery calcium is highly predictive of absence of “significant” (greater than 50%) coronary artery stenosis. In one particular series, patients with a score of 0 had a probability of significant coronary artery stenosis of < 1%