The Diagnostic Accuracy of 64-Detector Cardiac Computed Tomography Compared With Stress Nuclear Imaging in Patients Undergoing Invasive Cardiac Catheterization

OBJECTIVE: The aim of this study was to evaluate the diagnostic accuracy of nuclear stress imaging as compared with noninvasive coronary artery imaging using 64-detector row cardiac computed tomography. BACKGROUND: Compared with invasive coronary angiography, multidetector row cardiac computed tomographic angiography (CTA) has shown promise in the accurate detection of coronary stenosis. Myocardial perfusion imaging (MPI) using single photon emission computed tomography is an established method for noninvasively assessing the functional significance of coronary stenosis. This study compared the accuracy of CTA and that of MPI in the detection of relevant lesions of coronary arteries. METHODS: One hundred twenty-two symptomatic patients (77% males) with cardiac catheterization who also underwent MPI and CTA evaluations within 6 months at 2 centers were included. Comparison of CTA for lesions causing greater than 50% and greater than 70% coronary narrowing versus respective lesions on invasive cardiac catheterization (IC) was performed. Similarly, comparison of MPI findings with greater than 50% and greater than 70% lesions on IC was done. RESULTS: The per-patient sensitivity, specificity, and positive and negative predictive values in detecting greater than 50% coronary lesions on IC for CTA were 98.9%, 74.2%, 91.8%, and 95.8%, respectively; and for MPI, 56%, 38.7%, 72.9%, and 23%, respectively. The sensitivity, the specificity, and the positive and negative predictive values in detecting greater than 70% coronary lesions on IC for CTA were 89.7%, 86.4%, 92.1%, and 82.6%, respectively; and for MPI, 57.7%, 43.2%, 64.3%, and 36.5%, respectively. The prevalence of significant coronary artery disease on cardiac catheterization was 74.6% for greater than 50% stenosis and 63.9% for greater than 70% stenosis. CONCLUSIONS: Compared with MPI, CTA provided important information and identified significant lesions in symptomatic intermediate- to high-risk patients. Cost-effective and prospective multicentered studies, currently underway, are needed to further establish the best use of these diagnostic tests in the evaluation of coronary artery disease.