Evaluation of coronary stent patency and in-stent restenosis with dual-source CT coronary angiography without heart rate control.

OBJECTIVE: Dual-source CT has excellent temporal resolution and allows good visualization of coronary vessels without heart rate control. Our aim was to evaluate the diagnostic performance of dual-source CT in the evaluation of coronary stent patency to determine whether the good temporal resolution would improve visualization of stents.

SUBJECTS AND METHODS: Thirty-five consecutively registered patients (10 women, 25 men; mean age, 65 years) with 48 stents were examined prospectively without heart rate controlling agents. Observers evaluating image quality and patency of the stents were blinded to the results of invasive coronary angiography. In-stent restenosis was defined as more than 50% narrowing of the lumen.

RESULTS: All stents were considered assessable for diagnosis with dual-source CT. In 85% (41/48) of the stents, image quality was good. Only two patent stents were misidentified as being stenotic. All other stents with stenosis and occlusion were correctly diagnosed. The sensitivity, specificity, positive and negative predictive values, and accuracy of dual-source CT in the detection of in-stent restenosis and occlusion were 100%, 94%, 89%, 100%, and 96%, respectively. The McNemar test result showed no statistically significant difference between the diagnostic performance of dual-source CT and that of invasive coronary angiography. The kappa indexes showed excellent intraobserver and interobserver agreement.

CONCLUSION: The high temporal resolution of dual-source CT is helpful for evaluation of coronary stents without heart rate control. Further confirmation of our preliminary results may broaden the clinical indications for CT angiography as a diagnostic test for the exclusion of in-stent restenosis.