Evaluation of coronary artery in-stent patency using 64-slice computed tomography

Surveillance conventional coronary angiography (CCA) is recommended after stent supported percutaneous coronary intervention due to the unpredictable occurrence of in-stent restenosis (ISR). We explored the ability of 64-slice computed tomography angiography (CTA) to detect ISR after stenting of the coronary artery and analyzed the factors influencing imaging quality.

Forty-five consecutive patients (29 stents) were examined by both CCA and 64-slice CTA after percutaneous coronary intervention. We analyzed the correlation between the image quality and heart rate, diameter, position, and stent-strut thickness. Compared with the CCA, the sensitivity, specificity, positive predictive value, and negative predictive value of 64-slice CTA for the detection of ISR were calculated. Between the patent group and ISR group, different computed tomography attenuation values of the in-stent lumen and artery 5 mm proximal and distal to the stent were also analyzed.

All stents were clearly visualized. With regard to the differences in heart rate, stent position, stent diameter, and stent-strut thickness among the different image quality groups, the P values were 0.47, 0.60, 0.04, and <0.01, respectively. Compared with CCA, the sensitivity, specificity, positive predictive value, and negative predictive value of 64-slice CTA were 100, 95.2, 88.9, and 100%, respectively. Between patent and ISR groups, the P values for the differences in CTA attenuation values of the in-stent lumen and artery 5 mm distal to the stent were 0.007 and 0.04, respectively.

We found that 64-slice spiral CTA is a reliable noninvasive diagnostic method that can display the stent lumen clearly and is especially helpful for patient follow-up.