Relationship Between Optical Coherence Tomography–Derived In‐Stent Neoatherosclerosis and the Extent of Lipid‐Rich Neointima by Near‐Infrared Spectroscopy and Intravascular Ultrasound: A Multimodal Imaging Study

Abstract

Background In‐stent restenosis, especially for neoatherosclerosis, is a major concern following percutaneous coronary intervention. This study aimed to elucidate the association of features of in‐stent restenosis lesions revealed by optical coherence tomography (OCT)/optical frequency domain imaging (OFDI) and the extent of lipid‐rich neointima (LRN) assessed by near‐infrared spectroscopy (NIRS) and intravascular ultrasound, especially for neoatherosclerosis. Methods and Results We analyzed patients undergoing percutaneous coronary intervention for in‐stent restenosis lesions using both OCT/OFDI and NIRS–intravascular ultrasound. OCT/OFDI‐derived neoatherosclerosis was defined as lipid neointima. The existence of large LRN (defined as a long segment with 4‐mm maximum lipid core burden index ≥400) was evaluated by NIRS. In 59 patients with 64 lesions, neoatherosclerosis and large LRN were observed in 17 (26.6%) and 21 lesions (32.8%), respectively. Naturally, large LRN showed higher 4‐mm maximum lipid core burden index (median [interquartile range], 623 [518–805] versus 176 [0–524]; P <0.001). In OCT/OFDI findings, large LRN displayed lower minimal lumen area (0.9±0.4 versus 1.3±0.6 mm 2 ; P =0.02) and greater max lipid arc (median [interquartile range], 272° [220°–360°] versus 193° [132°–247°]; P =0.004). In the receiver operating characteristic curve analysis, 4‐mm maximum lipid core burden index was the best predictor for neoatherosclerosis, with a cutoff value of 405 (area under curve, 0.92 [95% CI, 0.83–1.00]). In multivariable logistic analysis, only low‐density lipoprotein cholesterol (odds ratio, 1.52 [95% CI, 1.11–2.08]) was an independent predictor for large LRNs. Conclusions NIRS‐derived large LRN was significantly associated with neoatherosclerosis by OCT/OFDI. The neointimal characterization by NIRS–intravascular ultrasound has potential as an alternative method of OCT/OFDI for in‐stent restenosis lesions.