Abstract 9330: In-stent Restenotic Tissue with a Microchannel in Patients with Diabetes: Insights from Coronary Optical Coherence Tomography Image Analysis

Abstract

Introduction Coronary optical coherence tomography (OCT) allows the detection of subtle differences in patients with coronary artery disease. To date, OCT can virtually depict the various histological findings that occur at in-stent restenotic tissue. The present study investigated the clinical implications of microchannels located in in-stent restenotic sites. Methods We examined 48 consecutive in-stent restenotic (stenosis area, >50%) coronary artery lesions from 44 patients who underwent coronary OCT. OCT images were obtained with a time-domain OCT imaging system. The images were acquired during automatic-pull back (1 mm/s; 20 frames/s). A microchannel was defined as the low signal cavity with a diameter of 50-150 µm (Figure; white arrows) and was evaluated by 2 independent analysts. A third analyst provided the final decision when there was a discrepancy between the first and second analysts. Diabetes was diagnosed in accordance with the guidelines of the Japanese Diabetes Society. Results In total, 16,008 frames were evaluated. Microchannels were detected in 464 (2.9%) frames from 24 (50%) lesions in 22 (50%) patients. The kappa statistic on the lesion level between the 2 analysts was 0.875. Diabetes was diagnosed in 23 (52.3%) patients, and 7 (15.9%) patients had insulin therapy. The incidence of microchannels was significantly more frequent in patients with diabetes (65.2% vs. 33.3%, p = 0.03). In contrast, none of the coronary risk factors (hypertension, dyslipidemia, smoking) other than diabetes showed a significant relationship with microchannel formation. Conclusion Microchannels were frequently observed at in-stent restenotic tissue sites in patients with diabetes. The results indicated that microvessel formation, which is a common diabetic complication, is a unique pathophysiological factor of in-stent restenosis in patients with diabetes. Neovascular formation may be targeted to prevent in-stent restenosis in patients with diabetes.