[Diagnostic value of 320-slice computed tomography coronary angiography to assess in-stent restenosis].

OBJECTIVE: To evaluate the diagnostic accuracy of 320-slice CT coronary angiography (CTA) in the evaluation of in-stent restenosis (ISR, ≥50% luminal narrowing) in comparison with quantitative coronary angiography (CAG). METHODS: A total of 69 patients with previous stent implantation who underwent both CTA and CAG were prospectively included. We assessed diagnostic valve for ISR with CTA in comparison with CAG. RESULTS: A total of 110 stents were implanted in these patients.CAG identified 14 ISR. CTA correctly identified 13 ISR and misdiagnosed 5 ISR in stents without ISR. Besides, 6 stents could not be evaluated by CTA due to unsatisfied image quality. Accordingly, sensitivity, specificity, positive and negative predictive value of CTA for diagnosing ISR were 93%, 89%, 54% and 99%, respectively. The image quality of CTA was significantly better in larger stents (percentages of good and moderate stent image of ≥3.0 mm and 0.05). CONCLUSIONS: Our results indicate that 320-slice CTA allows accurate noninvasive assessment of significant in-stent restenosis in selected patients. Stents with a large diameter and thin struts are associated with better image quality and higher diagnostic accuracy.