TCT-293 Neointimal Tissue Characteristics Based on Optical Coherence Tomography Analysis Following Paclitaxel Coated Balloon Treatment in a Porcine Iliofemoral Vascular Territory

Abstract

Background: The optical coherence tomography (OCT) characteristics of in-stent neointimal tissue have been associated with histological markers of healing. We aimed to investigate the differences in neointimal characteristics based on OCT analysis of Paclitaxel coated balloon (PCB) treatment versus POBA in the Iliofemoral territory of the familial hypercholesterolemic swine model (FHS). Methods: 14 Iliofemoral arterial segments of 7 FHS were balloon injured followed by a BMS placement. At 14 days, the injured sites were treated with either a PCB or POBA (control). OCT images, acquired at 28 days post inflation, were classified at every 2mm according to previously published classification of neointimal types (homogeneous, heterogeneous and layered). Quantitative morphometric evaluation of vessel, stent, microvessel and peristrut low intensity areas (PLI) presence was also performed. A multivariable logistic regression model was performed dividing the neointima into homogeneous and non-homogeneous. Results: AA total of 150 OCT cross sections were included in the final analysis. PCB resulted in a reduction of percent area stenosis (%AS) by 50% (PCB: 34 18% versus POBA 68 21%, p 0.05). The homogeneous pattern was more frequent in PCB (25%) than in the POBA group (3%, p 0.001). Conversely, the layered pattern was more prevalent in the POBA group (50.7% versus 4%, p 0.001). The homogeneous pattern correlated with less degree of neointimal formation [%AS: 16.68 5.3%, p 0.001) than the non-homogeneous group (heterogeneous: 49.01 24.9% and layered: 67.29 15.6%). The presence of micro vessels (89% versus 58%, p 0.001) and PLI (39% versus 24%, p 0.1) were more frequently found in the POBA group than in the PCB group. The only independent predictor of non-homogeneous patterns was the %AS [OR (95% CI)] [3.98(1.21-13.09)]. Conclusions: In vivo OCT analysis suggests that the biological effect of Paclitaxel delivered via DCB frequently results in the homogeneous development of neointimal formation and lower frequency of PLI and micro-vessels compared to a POBA control. These in vivo findings support the biological efficacy observed in clinical trials using this technology.