Combined coronary angiography and myocardial perfusion by computed tomography in the identification of flow-limiting stenosis – The CORE320 study: An integrated analysis of CT coronary angiography and myocardial perfusion

• Combined coronary CT angiography and myocardial CT perfusion is gaining acceptance.
• Analysis of both methods by the same reader is feasible and superior to CTA alone.
• A natural workflow is presented aiming the implementation in the clinical setting.

BackgroundThe combination of coronary CT angiography (CTA) and myocardial CT perfusion (CTP) is gaining increasing acceptance, but a standardized approach to be implemented in the clinical setting is necessary.ObjectivesTo investigate the accuracy of a combined coronary CTA and myocardial CTP comprehensive protocol compared to coronary CTA alone, using a combination of invasive coronary angiography and single photon emission CT as reference.MethodsThree hundred eighty-one patients included in the CORE320 trial were analyzed in this study. Flow-limiting stenosis was defined as the presence of ≥50% stenosis by invasive coronary angiography with a related perfusion defect by single photon emission CT. The combined CTA + CTP definition of disease was the presence of a ≥50% stenosis with a related perfusion defect. All data sets were analyzed by 2 experienced readers, aligning anatomic findings by CTA with perfusion defects by CTP.ResultsMean patient age was 62 ± 6 years (66% male), 27% with prior history of myocardial infarction. In a per-patient analysis, sensitivity for CTA alone was 93%, specificity was 54%, positive predictive value was 55%, negative predictive value was 93%, and overall accuracy was 69%. After combining CTA and CTP, sensitivity was 78%, specificity was 73%, negative predictive value was 64%, positive predictive value was 0.85%, and overall accuracy was 75%. In a per-vessel analysis, overall accuracy of CTA alone was 73% compared to 79% for the combination of CTA and CTP (P < .0001 for difference).ConclusionsCombining coronary CTA and myocardial CTP findings through a comprehensive protocol is feasible. Although sensitivity is lower, specificity and overall accuracy are higher than assessment by coronary CTA when compared against a reference standard of stenosis with an associated perfusion defect.