Evaluation of patients with previous coronary stent implantation with 64-section CT

Abstract

Purpose: To prospectively evaluate the diagnostic accuracy of 64-section computed tomography (CT) for the assessment of in-stent or peristent restenosis, with conventional coronary angiography as the reference standard.

Materials and methods: The study was approved by the medical ethics committee, and informed consent was obtained in all 50 enrolled patients (40 men, 10 women; mean age, 60 years +/- 11 [standard deviation]). In addition to conventional coronary angiography with quantitative coronary angiography, 64-section CT was performed. For each stent, assessability was determined and was related to stent characteristics and heart rate by using a chi(2) test. On the interpretable images of stents and peristent lumina (5.00 mm proximal and distal to the stent), the presence of significant (> or =50%) restenosis was determined. For this analysis, partially overlapping stents were considered to represent a single stent.

Results: Of 76 stents, 65 (86%) were determined to be assessable. Increased heart rate and overlapping positioning were associated with increased uninterpretability of the images of stents (P < .05), whereas location of the stent and thickness of the strut were not. In seven patients, stents were placed in an overlapping manner, resulting in 58 stents available for the evaluation of significant (> or =50%) in-stent restenosis. All six significant (> or =50%) in-stent restenoses were detected, and the absence of significant (> or =50%) restenosis was correctly identified in the 52 remaining stents, resulting in sensitivity and specificity of 100%. Sensitivity and specificity for the detection of significant (> or =50%) peristent stenosis were 100% and 98%, respectively.

Conclusion: In selected patients with previous stent implantation, 64-section CT can be used to evaluate in-stent restenosis with high accuracy. Accordingly, the technique may be useful for noninvasive exclusion of in-stent or peristent restenosis, thereby avoiding invasive imaging in a considerable number of patients.