Evaluation of coronary in-stent restenosis by 64-slice computed tomography in patients with optimal heart rate control by systematic administration of beta-blocker drugs.

Background: Imaging artifacts due to metallic stent struts can reduce the diagnostic accuracy of multislice computed tomography (MSCT) in the evaluation of in-stent restenosis (ISR). Our aim was to determine the accuracy of binary ISR exclusion using a 64-slice MSCT scanner and a systematic administration of beta-blockers having an aggressive heart rate (HR) control.

Methods: We performed 64-slice MSCT in 218 consecutive patients revascularized by stenting. All patients were treated with oral/intravenous beta-blocker drugs in order to obtain a HR less than 65 beats/min in the prescan phase. Coronary stents were evaluated by two experienced observers in order to rule out the presence of significant (>50%) ISR. Quantitative conventional coronary angiography (CCA) served as a standard for reference.

Results: Five patients (2.3%) were excluded from the analysis; mean HR was 59 +/- 3 beats/min in the prescan phase and 62 +/- 5 beats/min during acquisition. In the 321 stented coronary segments, CCA found 27 significant ISRs. MSCT correctly diagnosed 26 significant ISRs, with two false-positive and one false-negative case. In a per-segment analysis, the sensitivity was 96%, specificity 99%, positive predictive value (PPV) 92.8%, and negative predictive value (NPV) 99%. In a per-patient analysis, the sensitivity was 100%, specificity 98.9%, PPV 92.8%, and NPV 100%.

Conclusion: In our study, the evaluation of significant ISR by MSCT showed an excellent diagnostic accuracy with a PPV of 92.8% and a NPV of 99%. Selection criteria and radiation exposure can be considered a limitation of the method.