Abstract 15522: Thin-Strut Fully Absorbable Scaffold With Favorable Endothelial Shear Stress Profile Reduces Inflammation and Promotes Rapid Arterial Healing: A Serial Dual-Modal Optical Coherence Tomography-Near Infrared Fluorescence (OCT-NIRF) Molecular Imaging Study

IntroductionDuring scaffold absorption, protruded dismantling struts and inflammation influence endothelial shear stress (ESS) and vascular healing process. We aimed to estimate dynamic changes of local ESS and arterial healing response including active inflammation in a thin-strut poly-L-lactide bioresorbable scaffold (BRS, 100μm) compared to first-generation 157μm-thickness ABSORB.Methods and ResultsBRS and ABSORB were implanted in left anterior descending and circumflex arteries of the same pigs (n=5), respectively. 3D scaffolded-artery model for computational fluid dynamics was reconstructed based on OCT imaging. To estimate scaffold-related inflammation response, serial integrated OCT-NIRF imaging was performed following injection of macrophage mannose receptor-Cy7 as an inflammation-targeted NIRF emitter. On ESS analysis, difference in strut thickness significantly affected local hemodynamics, demonstrating favorable high ESS in thin-BRS compared to ABSORB. Serial OCT-NIRF structural-molecular imaging clearly visualized active inflammation with peri-strut tissue formation in vivo. Arterial inflammation, quantified as target-to-background ratio (TBR, Figure), was significantly lower in thin-BRS than ABSORB at 2 weeks (p