Evaluation Of Coronary Artery In-srent Restenosis Using Computed Tomography Angiography

Objective To evaluate the feasibility of coronary artery in-stent restenosis using computed tomography angiography.Methods94patients (155stents) were examined by dual-source computed tomography angiography (CTA) after percutaneous coronary intervention, to evaluate the image quality. Compare with the coronary angiography (CAG), the accuracy of dual-source CTA for the detection of in-stent restenosis were calculated. Between the patent group and in-stent restenosis group determined by CAG, computed tomography attenuation values of the stent segment were measured, attempted to seek the cut-off value to diagnosis in-stent restenosis.Result The image quality of in-stent lumen examined by dual-source CTA was high. Stent diameter was the main influencing factor of image quality; however, stent-strut thickness and stent position were not related to image quality.62of155stents were confirmed to be in-stent restenosis. Compare with the coronary angiography (CAG), the sensitivity, specificity, positive predictive value, negative predictive value, and accordance of dual-source CTA for the detection of in-stent restenosis were82.3%,80.6%,73.9%,87.2%and81.3%. Between patent group and ISR group confirmed by CAG, the P values for the differences in computed tomography attenuation D-value of the artery5mm proximal to the stent, the proximal end artery of the stent, the in-stent lumen, the distal end artery of the stent and the artery5mm distal to the stent were0.368,0.006,0.000,0.021and0.006, respectively. To diagnosis in-stent restenosis, the most appropriate cut-off value of computed tomography attenuation D-value of the artery5mm proximal to the stent, the proximal end artery of the stent, the in-stent lumen, the distal end artery of the stent and the artery5mm distal to the stent were6.5Hu,-2.0Hu,37.5Hu,25.5Hu and59.0Hu, respectively.Conclusion The in-stent lumen after percutaneous coronary intervention could be examined by dual-source CTA clearly, moreover, the sensitivity, specificity, positive predictive value and negative predictive value were all high. Measurement of computed tomography attenuation values and the application of cut-off value of the stent segment are hopeful to be objective methods to diagnose in-stent restenosis.