Contrast-enhanced 64-section coronary multidetector CT angiography versus conventional coronary angiography for stent assessment.

PURPOSE To prospectively evaluate the accuracy of 64-section computed tomography (CT) for diagnosis of stent restenosis, by using conventional coronary angiography as the reference standard. MATERIALS AND METHODS The ethics committee granted permission for the study; patients gave written consent. Contrast material-enhanced coronary CT angiography was performed in 53 patients (45 men, eight women; mean age, 54 years +/- 9 [standard deviation]) suspected of having stent restenosis. Coronary CT angiographic findings were compared with conventional coronary angiographic findings. Two physicians analyzed coronary CT angiographic data sets with multiplanar reformatted images and three-dimensional reformations by using a volume-rendering technique and looked for stent detectability, low-attenuation in-stent filling defects, and grades of restenosis. Conventional coronary angiographic results were interpreted by one of several observers in consensus for stent restenosis; they were blinded to coronary CT angiographic data. Statistical software and general estimating equations were used for data analysis. RESULTS One hundred ten stents were identified in 53 patients. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of coronary CT angiography in detection of in-stent restenosis were 96.9%, 88.0%, 77.5%, 98.5%, and 91%, respectively. Coronary CT angiography depicted in-stent low-attenuation filling defects with an accuracy of 91% and negative predictive value of 98.5% (95% confidence interval: 90.9, 99.9). Coronary CT angiography depicted the status of 97 of 107 stents. There was no significant difference between in-stent lumen visibility and stent diameter (P = .104). Coronary CT angiography helped diagnose 15 of 18 stent restenoses with less than 50% narrowing, five of five stent restenoses with 50%-74% narrowing, and nine of nine (100%) stent restenoses with 75% or greater narrowing or total occlusion of the stent lumen. CONCLUSION Coronary CT angiography can depict in-stent low-attenuation filling defects, which appear to be a reliable sign of stent restenosis, and 64-section CT depicts such defects with a high degree of accuracy.