Abstract 15391: Imaging Comparison of in-Stent Restenosis Findings by Optical Coherence Tomography: Focus on Vasa Vasorum and Peri Stent-Strut Low Intensity Area.
Background: Recently, It was reported that chronic thrombosis or inflammation are causative factors of in-stent restenosis (ISR) after drug eluting stent (DES) implantation. On the other hand, previous studies showed that the progression of vasa vasorum relates to DES implantation and diabetes mellitus. However, the relation between ISR and vasa vasorun remains unclear.
Objective: The purpose of this study is to evaluate the characteristics of ISR and the incidence of vasa vasorum in patients with ISR by Optical Coherence Tomography (OCT).
Methods: OCT was performed in consecutive 53 patients with ISR after coronary stent implantation at follow-up. Patients were classified into three groups, bare metal stent (BMS) for acute coronary syndrome (ACS) group (BMS-ACS) (n=25), BMS for chronic coronary artery disease (CAD) group (BMS-CAD) (n=12), and DES-CAD group (n=16). We assessed ISR characteristics with regard to homogeneity, attenuated signal backscattering, micro-channels in NIH, vasa vasorum, and peri stent-strut low intensity areas of NIH.
Result: The incidence of homogeneous images in NIH was significantly different among the groups (48.0% vs. 41.7% vs. 6.3%, respectively; p=0.01). Vasa vasorum formations were significantly higher in the BMS-CAD group than in the other 2 groups (48.0% vs. 83.3% vs. 37.8%, respectively; p=0.04). Peri stent-strut low intensity areas were observed in 80.0% in the BMS-ACS group and 58.3% in the BMS-CAD group. In the DES-CAD group, low intensity areas were only observed in 6 of 8 cases (75%) and could not be observed in the other 8 cases because of massive amount of thrombi and heterogeneous tissue. Multivariate logistic regression analysis showed diabetes mellitus was a significant risk factor for vasa vasorum formation (odds ratio 4.09, 95% CI: 1.198–13.98; p=0.02).
Conclusion: The homogeneity rate in DES-CAD group was significantly lower than in the other groups, and the frequency of peri stent-strut low intensity area was equal to that of BMS-ACS group (75% vs. 80%). This might indicate the presence of inflammation as a cause of ISR in patients treated with DES. Vasa vasorum formation in ISR visualized by OCT related to diabetes mellitus. OCT images may provide a detailed evaluation of ISR characteristics of NIH.
- © 2010 by American Heart Association, Inc.