In patients at low-to-intermediate risk of coronary artery disease (CAD), CCTA is a viable alternative to functional stress tests and may facilitate triage decisions, as well as reduce the risk of missed myocardial infarctions and length of hospital stay (1,2). Although compared to conventional coronary angiography CCTA has lower specificity (64-90%), it has consistently been shown to have high sensitivity (>95%) and negative predictive values (>95%) for obstructive coronary stenosis, supporting its potential role in “ruling out” significant CAD in low-to-intermediate risk patients (1-2).
A coronary artery calcification (CAC) score is also commonly measured when CCTA is performed; a very high CAC score can interfere with proper interpretation of CCTA. A negative CCTA combined with a CAC score of zero makes CAD-related chest pain extremely unlikely. The additional prognostic value of CAC score other than zero to CCTA is unclear (2).
- Budoff MJ, Dowe D, Jollis JG, et al. Diagnostic performance of 64-multidetector row coronary computed tomographic angiography for evaluation of coronary artery stenosis in individuals without known coronary artery disease: results from the prospective multicenter ACCURACY (Assessment by Coronary Computed Tomographic Angiography of Individuals Undergoing Invasive Coronary Angiography) trial. J Am Coll Cardiol. 2008;52(21):1724.
- Villines TC, Hullen EA, Shaw LJ, et al. Prevalence and severity of coronary artery disease and adverse events among symptomatic patients with coronary artery calcification scores of zero undergoing coronary computed tomography angiography results from the CONFIRM (Coronary CT Angiography Evaluation for Clinical Outcomes: an International Multicenter) registry. J Am Coll Cardiol 2011;58:2533-2540.
Contributed by Stephanie Meller, MD, Boston, MA.