SAN FRANCISCO – Coronary CT angiography outperformed myocardial perfusion single-photon emission CT for the diagnosis of obstructive coronary artery disease in a prospective multicenter head-to-head comparative study.
The CORE320 (Coronary Artery Evaluation Using 320-Row Multidetector Computed Tomography Angiography and Myocardial Perfusion) study included 381 patients with suspected or known coronary artery disease (CAD) who were scheduled for invasive quantitative coronary angiography. But first they all underwent coronary CT angiography (CTA) and single-photon emission CT (SPECT), with images analyzed in blinded independent core laboratories. The time interval between the two imaging studies was a mean of 9.4 days. Invasive coronary angiography served as the diagnostic reference standard in the 16-center, 8-country study, Dr. Marcelo F. Di Carli explained at the annual meeting of the American College of Cardiology.
The primary study endpoint was test accuracy as defined by the area under the receiver operating characteristic curve for identifying the 59% of subjects with at least a 50% stenosis by invasive coronary angiography. The rate was significantly better for CTA than SPECT: 89% vs. 69%.
CTA’s superior performance was driven by its greater sensitivity in detecting stenoses of 50% or more: 91% vs. 62% for SPECT. The two imaging modalities displayed similar specificity: 74% for CTA and 67% for SPECT.
CTA had a positive predictive value of 83% and a negative predictive value of 85%, compared with 73% and 55%, respectively, for SPECT, according to Dr. Di Carli of Brigham and Women’s Hospital, Boston.
The same pattern of results was seen with regard to diagnostic accuracy in detecting patients with at least a 70% stenosis, a prespecified secondary endpoint. CTA had 94% sensitivity, 60% specificity, a positive predictive value of 66%, and a negative predictive value of 92%. SPECT showed 72% sensitivity, 67% specificity, a 64% positive predictive value, and a 73% negative predictive value.
The average radiation dose was markedly lower with CTA: 3.54 mSv compared with 10.48 mSv for SPECT.
The study was funded by Toshiba. Dr. Di Carli reported having no relevant financial conflicts.