Assessment of Vascular Response after Stent Implantation by Intracoronary Optical Coherence Tomography

Abstract

Optical coherence tomography (OCT) is a high resolution (10-20 μm) imaging modality that provides microscopic visualization of the coronary artery including vascular response after stent implantation. Compared to conventional intravascular ultrasound, OCT can more clearly identify findings immediately after stent implantation, such as tissue protrusion, stent edge dissection, and incomplete stent strut apposition. Furthermore, OCT allows clinicians to accurately assess the late acquired stent malapposition and strut coverage which could be a surrogate marker for stent thrombosis after drug-eluting stent (DES) implantation. OCT can evaluate not only the extent and amount of neointima but also the tissue characteristics of neointimal hyperplasia. Morphological OCT evaluation of restenosis tissue may offer important information about treatment strategies for in-stent restenosis lesion as well as the acute/mid-term clinical outcome after percutaneous coronary intervention. In addition, in-stent neoatherosclerosis, which are associated with very late stent failure, including stent thrombosis and restenosis, frequently has the following OCT findings; lipid-rich neointima, microvascular proliferation, and neointimal disruption. Thus, the high resolution imaging of OCT has provided important insights into the vascular response immediately and late after stent implantation.