Perspective:

This large multicenter trial nicely demonstrates a substantial and clinically relevant overestimation of the prevalence of CAD by the currently recommended ACC/AHA algorithm, which is an integral part of guidelines for evaluation of patients with stable angina, and are also utilized as part of multiple other documents including appropriate use criteria for stress echocardiography and myocardial perfusion. CTA is well established as an accurate method for determining the presence and severity of CAD, and there is no reason to think that invasive coronary arteriography performed in this same patient population would provide different results. The authors propose several reasons for the overestimation by the current clinical guidelines, including the fact that they are based on studies utilizing invasive coronary arteriography. In many instances, patients being referred for invasive coronary arteriography will represent a different clinical subset than those being more electively evaluated with CTA and probably do represent a population with higher risk for significant obstructive disease than the population noted here. Of note, in addition to overestimation by the ACC/AHA guidelines, other clinical predictors, which include multiple risk factors, also overstated the prevalence of disease as actually found. Previous algorithms for predicting the prevalence of CAD have all demonstrated a hierarchy of presence based on increasing age as well as a higher prevalence of CAD for males across all age ranges, which was confirmed here, although at substantially lower absolute levels of prevalence. This very well done study provides information that is crucial for understanding the performance of other noninvasive strategies for the detection of CAD, and caution is advised in utilizing noninvasive strategies for predicting the presence of CAD as it applies to the appropriateness of subsequent testing.