Diagnostic Accuracy of Anatomic Testing for the Initial Diagnosis of SIHD 2.2.4.1. Coronary CT Angiography With improvements in temporal and spatial resolution as well as volume coverage, evaluation of coronary arteries with CCTA is now possible with a high degree of image quality.208 The extent and severity of angiographic CAD are 2 of the most important prognostic factors and remain essential for revascularization decision making.209 Five meta-analyses and 3 controlled clinical trials have reported the diagnostic accuracy of CCTA with 64-slice CT, yielding sensitivity values ranging from 93% to 97% and specificity values ranging from 80% to 90%159 166 for detecting obstructive CAD on invasive coronary angiography, unadjusted for referral bias. In a small series of women, the diagnostic accuracy of CCTA was similarly high.210 Prior reports in- cluded subsets of patients who already had been referred for invasive angiography, and as such, test performance would be altered by the biases inherent in a preselected population. Factors related to diminished accuracy include image quality, the extent of coronary calcification, and body mass index A potential advantage of CCTA over standard functional testing is its very high negative predictive value for obstruc- tive CAD, which can reassure caregivers that providing GDMT and deferring consideration of revascularization con- stitute a sensible strategy. 