Assessment of coronary artery stents by 16 slice computed tomography

To analyse coronary stents with multislice spiral computed tomography (MSCT) in comparison with coronary angiography.

310 patients referred for conventional coronary angiography underwent MSCT on the next day (16 x 0.75 mm cross section, 420 ms rotation, 110 ml contrast agent intravenously at 4 ml/s). Two independent blinded reviewers analysed the MSCT.

143 patients had previous stenting (232 stents) and 190 (82%) of the 232 stents were detected. Intrastent lumen was interpretable in 126 (64%) of the detected stents. Lumen interpretability depended on stent diameter: for stent diameter > 3 mm, 81% of lumens were interpretable, as against 51% with < or = 3 mm stent diameter (p < 0.001). Restenosis detection likewise depended on stent diameter: with small stents (< or = 3 mm), sensitivity and specificity of MSCT were 54% and 100%, respectively; positive and negative predictive values were 100% and 94%. For stents with > 3 mm diameter, corresponding values were 86%, 100%, 100%, and 99%.

16 slice MSCT allows analysis of in-stent lumen in about half of all stented angioplasties. It performs better when stent diameter is more than 3 mm and may offer a non-invasive alternative to conventional coronary angiography for monitoring stented coronary arteries. Technical progress may improve interpretability and hence increase the yield of MSCT in this application.