Noninvasive Coronary Angiography with 64-Channel Multidetector Computed Tomography in Patients with Acute Coronary Syndrome

Background: Advances in computer tomography (CT) imaging technology in recent years have facilitated the possibility of noninvasive coronary angiography. Purpose: To compare the diagnostic accuracy of 64-channel multidetector computed tomography (MDCT) with conventional invasive coronary angiography (ICA) for the detection of significant coronary stenosis in patients with acute coronary syndrome (ACS). Material and Methods: MDCT was performed in 60 patients classified with non-ST-elevation infarction (NSTEMI) or unstable angina and scheduled for ICA within 3 days. The diagnostic accuracy of MDCT was evaluated using quantitative coronary angiography (QCA) as the gold standard. Results: 48 out of 60 patients had interpretable scans by both MDCT and ICA. On a segment-based analysis, 488 out of 665 segments with a diameter of ≥1.5 mm, as defined by QCA, were interpretable by MDCT. Sensitivity was 78%, specificity 87%, positive predictive value 47%, and negative predictive value 97% in detecting and excluding significant coronary stenosis, as defined with MDCT. On a per patient-based analysis, sensitivity was 89%, specificity 50%, positive predictive value 84%, and negative predictive value 60%. Conclusion: Limited diagnostic accuracy restricts the usefulness of coronary MDCT in patient groups with a high pretest probability of disease, such as in acute coronary syndrome.