When should each of these noninvasive imaging techniques be used in clinical practice?
- A coronary calcium scan (CCS) is used to answer the related questions: What is the CCS score-adjusted cardiovascular risk of this asymptomatic patient? Is modification of lipid-lowering or other therapy required, and if so what is the target LDL-cholesterol level?
- Its application is in the primary prevention setting in the asymptomatic patient, and it is a tool for estimation of CVD risk.
- Coronary CT angiography (CCTA) is a different test, and addresses the question: Does this symptomatic patient have a coronary stenosis or anomaly that explains the presenting symptoms?
- Its application (as is the case for routine invasive angiography) applies to diagnosis in the secondary prevention setting, and it is a tool for defining the anatomy of native coronary arteries or of coronary bypass grafts in symptomatic patients.
- Both a CCS and CCTA have the potential to change diagnosis and management in selected patients, when used appropriately.