Usefulness of 64-Slice Multidetector Computed Tomography for Detecting Drug Eluting In-Stent Restenosis

The aim of this study was to evaluate the accuracy of a new-generation spiral multidetector computed tomographic scanner (the Brilliance 64) in the diagnosis of coronary in-stent restenosis (ISR). Forty-one patients with 87 coronary stents (70 drug-eluting stents) implanted were examined. Patients underwent multidetector computed tomography (MDCT) 6.7 ± 6.9 days before scheduled invasive coronary angiography, using intravenous contrast enhancement. Images were reconstructed in multiple formats using retrospective electrocardiographic gating. Stents were viewed in their long and short axes and were visually classified for the presence or absence of binary ISR (diameter reduction >50%), including the 5-mm borders proximal and distal to the stent. ISR was found by invasive coronary angiography in 13 of the stented segments (15%) and in 8 patients (19%). Of these, 11 cases of ISR were correctly detected by MDCT; additionally, 1 severely calcified stented segment was considered as occluded by MDCT (sensitivity 84%, 95% confidence interval [CI] 54% to 98%). Seventy-three of 74 stented segments without ISR were correctly classified by MDCT (specificity 97%, 95% CI 93% to 100%), whereas 2 stented segments were classified as false-negative ISR. The positive predictive value was 92% (95% CI 84% to 97%), the negative predictive value was 97% (95% CI 90% to 99%), and predictive accuracy was 96% (95% CI 90% to 99%). After the exclusion of the calcified stented segment, the sensitivity, specificity, positive predictive value, negative predictive value, and predictive accuracy were 84% (95% CI 74% to 91%), 100% (95% CI 96% to 100%), 100% (95% CI 96% to 100%), 97% (CI 90% to 99%), and 98% (95% CI 92% to 99%), respectively. In conclusion, even with improved scanner technology, the sensitivity for the detection of ISR was moderate (84%). Thus, further studies are needed to determine whether MDCT will be a clinically useful and cost-effective tool for the evaluation of ISR in the clinical arena.