Assessment of coronary artery stent restenosis by 64-slice multi-detector computed tomography

Aims We investigated the feasibility of assessing coronary artery stent restenosis using a new generation 64-slice multi-detector computed tomography-scanner (MDCT) in comparison to conventional quantitative angiography. Methods and results MDCT was performed in 64 consecutive patients (mean age 58 +/- 10 years) with previously implanted coronary artery stents (102 stented lesions: mean stent diameter 3.17 +/- 0.38 mm). Each stent was classified as 'evaluable' or 'unevaluable', and in evaluable stents, the presence of in-stent restenosis (diameter reduction > 50%) was determined visually. Results were verified against invasive, quantitative coronary angiography. Fifty-nine stented lesions (58%) were classified as evaluable in MDCT. The mean diameter of evaluable stents was 3.28 +/- 0.40 mm, whereas the mean diameter of non-evaluable stents was 3.03 +/- 0.31 mm (P=0.0002). Overall, six of 12 in-stent restenoses were correctly detected by MDCT [50% sensitivity (confidence interval 22-77%)] and in 51 of 90 lesions, in-stent restenosis was correctly ruled out [57% specificity (46-67%)]. In evaluable stents, six of seven in-stent restenoses were correctly detected, and the absence of in-stent stenosis was correctly identified in 51 of 52 cases [sensitivity 86% (42-99%) and specificity 98% (88-100%)]. Conclusion Stent type and diameter influence evaluability concerning in-stent restenosis by MDCT. The rate of assessable stents is low, but in evaluable stents, accuracy for detection of in-stent restenosis can be high.