Abstract 14584: Diagnostic Accuracy of Coronary CT Angiography versus Invasive Coronary Angiography for the Diagnosis of Lesion-Specific Ischemia: A Direct Comparison to Fractional Flow Reserve
Background: Coronary CT angiography (CT) has emerged as a non-invasive method for accurate detection and exclusion of high-grade coronary stenoses as compared to invasive coronary angiography (ICA) as the reference standard. Fractional flow reserve (FFR) is the gold standard for determining lesion-specific ischemia, and has been shown to better identify lesions that improve outcomes with revascularization. We compared the diagnostic performance of CT to QCA for detection of lesion-specific ischemia using FFR as the gold standard.
Methods: 252 patients from 17 centers in 5 countries were prospectively enrolled (mean age 63 years, 71% male). Patients underwent CT and ICA with FFR in 407 lesions. CT, QCA and FFR were interpreted by independent core laboratories. Stenosis severity by CT was graded as 0-29%, 30-49%, 50-69%, and 70-100%, with stenosis ≥50% considered anatomically obstructive. QCA was classified as same manner. Lesion-specific ischemia was defined by FFR ≤0.8, while QCA and CT stenosis ≥50% were considered obstructive. Diagnostic accuracy and areas under the receiver-operating-characteristics curve (AUC) for lesion-specific ischemia was assessed.
Results: By FFR, ischemia was present in 151 of 407 lesions (37%). Diagnostic accuracy, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were 69%, 79%, 63%, 55% and 83% for CT; and 71%, 74%, 70%, 59% and 82% for QCA. AUC for identification of ischemia-causing lesions was similar, 0.75 for CT and 0.77 for QCA (p=0.6). No differences between CT and QCA existed for discrimination of ischemia within the left anterior descending artery (AUC 0.71 vs. 0.73, p=0.6), left circumflex artery (AUC0.78 vs. 0.85, p=0.4), right coronary artery (AUC 0.80 vs. 0.83, p=0.6).
Conclusions: CT and ICA demonstrate similar diagnostic performance for detection and exclusion of lesion-specific ischemia. Using a true reference standard to determine appropriate revascularization targets, three-dimensional CT angiography performs as well as two-dimensional ICA.
- © 2013 by American Heart Association, Inc.