Feasibility of assessment of coronary stent patency using 16-slice computed tomography

Intracoronary stent implantation is a frequently performed procedure in the treatment of stenoses in coronary arteries, but in-stent restenosis occurs in approximately 10% to 15% of patients. A noninvasive diagnostic procedure to evaluate in-stent restenosis would therefore be of great benefit. We investigated the feasibility of assessing stent patency with 16-slice computed tomography. Multislice computed tomography (MSCT) was performed in 22 patients with previously implanted stents. For each stent, assessability was determined and related to stent type and diameter. Subsequently, the presence of significant restenosis was determined in the evaluable stents. In addition, peristent lumina (5 mm proximal and distal to the stent) were evaluated. Conventional angiography in combination with quantitative coronary angiography served as the standard of reference. MSCT was performed successfully in all but 1 patient. Of 65 stents, 50 (77%) were determined assessable. Uninterpretable stents tended to have a thicker strut and/or a smaller diameter. In the evaluable stents, 7 of 9 stenoses were detected and the absence of restenosis was correctly identified in all 41 patent stents, resulting in a sensitivity and specificity of 78% and 100%, respectively. Sensitivity and specificity for the detection of peristent stenosis were 75% and 96%, respectively. In conclusion, MSCT may be useful in the assessment of stent patency and may function as a gatekeeper before invasive diagnostic procedures.