Coronary calcification: Achilles’ heel in the assessment for coronary artery disease in patients with symptomatic angina?

Excerpt

Coronary calcium quantification has emerged as a reliable and independent predictor of adverse cardiovascular events. Advances in multidetector scanning and imaging protocols have resulted in decreased contrast volumes, shorter scan times, and decreased radiation exposure, as well as improved spatial resolution and enhanced image quality. In subsets of patients with high calcium scores (particularly ≥400), however, the artifactual effects and scatter associated with radiodense calcium deposits have limited the specificity of CT coronary angiography (CTCA) in delineating the extent of clinically significant coronary artery disease (CAD). In the present study in the International Journal of Cardiovascular Imaging, Meijs et al. [1] conduct a multicenter prospective analysis of the diagnostic performance of 64-CTCA to predict the incidence of CAD in 360 patients who had been referred for conventional invasive coronary angiography (ICA) on the basis of symptomatic angina (stable and unstable) regardless of coronary calcium score (CS) over a 2-year time interval. As expected, the incidence of significant CAD correlated with increased CS. In patients with a CS ≥ 400, the prevalence of significant CAD was 87% as compared to 24% in those with a CS < 10. The specificity of CTCA as well as the positive likelihood ratio for significant CAD decreased significantly, however, as the CS increased. In patients with a CS < 10, the specificity was 89% (95%CI 76–96%) while in patients with CS > 400, the specificity was only 20% (95%CI 5–49%) [1]. …