Role of Near-Infrared Spectroscopy (NIRS) in Intracoronary Imaging

Purpose of ReviewThe purpose of this article is to review the basic principles of near-infrared spectroscopy (NIRS) and its contemporary role in intracoronary imaging.Recent FindingsNIRS has been demonstrated to effectively detect culprit lesions in acute coronary syndromes (ACS) and to potentially identify vulnerable plaque. Lipid-rich plaques detected by NIRS are also associated with higher incidence of future adverse cardiac events. Plaques with high lipid content detected by NIRS have been shown to predict periprocedural myocardial infarction during percutaneous coronary intervention (PCI). The beneficial effects of high-intensity statin therapy in terms of plaque regression and plaque stabilization have also been demonstrated using NIRS.SummaryNIRS is a valuable intracoronary imaging tool to assess lipid burden in atherosclerotic plaques and has been validated against histopathologic data. The commercially available dual-modality NIRS-intravascular ultrasound (IVUS) catheter further provides complementary data regarding lesion and vessel characteristics, thereby facilitating planning and optimization of PCI. Finally, the ability of NIRS to detect vulnerable plaque opens up potential new opportunities for risk stratification and intensification of secondary preventive measures.