Inflammatory Phenotype by OCT Coronary Imaging: Specific Features Among De Novo Lesions, In-Stent Neointima, and In-Stent Neo-Atherosclerosis

Abstract Background Coronary stenosis can be caused de novo atherosclerosis, in-stent restenosis, and in-stent neoatherosclerosis, three entities that develop from a diverse pathophysiological milieu. Objective This study aims to investigate, using optical coherence tomography (OCT), whether or not coronary lesions related to these processes differ in their local inflammatory profile. Methods Retrospective analysis of patients with diagnosed or suspected coronary lesions who had undergone OCT imaging for clinical reasons. Macrophage and intra-plaque neovascularization were assessed by OCT and used as surrogates of local inflammation. A significance level of < 0.05 was adopted as statistically significant. Results From the 121 lesions, 74 were de novo, 29 were restenosis, and 18 were neoatherosclerosis. Neovascularization was found in 65.8% of de novo, 10.3% in restenosis, and 94.4% in neoatherosclerosis (p<0.01 for all). The volume of neovascularization was different among lesion types (950 vs. 0 vs. 6220, respectively [median values in 1000 x µm3/mm]; p<0.01 for all), which were significantly higher in neoatherosclerosis and lower in restenosis. The presence of macrophages differed among the lesions (95.9% in de novo vs. 6.9% in restenosis vs. 100% in neoatherosclerosis [p<0.01 for all]). Moreover, the intensity of macrophagic infiltration was different among lesion types (2.5 vs. 0.0 vs. 4.5, respectively [median values of macrophage score]; p<0.01 for all), significantly higher in neoatheroscleosis and lower in restenosis. Conclusion When compared using coronary OCT, de novo atherosclerosis, in-stent restenosis, and neoatherosclerosis presented markedly different inflammatory phenotypes.

【摘要 背景】冠状动脉狭窄可由新发动脉粥样硬化、支架内再狭窄及支架内新生动脉粥样硬化这三种病理生理机制各异的病变引发。
【研究目的】本研究旨在借助光学相干断层成像（optical coherence tomography, OCT），探究与上述三种病变相关的冠状动脉病灶在局部炎症特征方面是否存在差异。
【研究方法】本研究为回顾性分析，纳入因临床指征接受OCT成像检查、确诊或疑似存在冠状动脉病灶的患者。以OCT评估巨噬细胞及斑块内新生血管情况，将其作为局部炎症的替代标志物。本研究采用P<0.05作为统计学显著性阈值。
【研究结果】本研究共纳入121处病灶，其中74处为新发动脉粥样硬化病灶，29处为支架内再狭窄病灶，18处为支架内新生动脉粥样硬化病灶。三类病灶的新生血管检出率分别为：新发动脉粥样硬化病灶65.8%、支架内再狭窄病灶10.3%、支架内新生动脉粥样硬化病灶94.4%（各组间比较P均<0.01）。不同病灶类型的新生血管体积存在显著差异（中位数分别为950、0、6220，单位：1000×μm³/mm；各组间比较P均<0.01），其中支架内新生动脉粥样硬化病灶的新生血管体积显著更高，支架内再狭窄病灶则显著更低。巨噬细胞检出率在三类病灶间存在显著差异：新发动脉粥样硬化病灶为95.9%，支架内再狭窄病灶为6.9%，支架内新生动脉粥样硬化病灶为100%（各组间比较P均<0.01）。此外，不同病灶类型的巨噬细胞浸润强度亦存在显著差异（巨噬细胞评分中位数分别为2.5、0.0、4.5；各组间比较P均<0.01），其中支架内新生动脉粥样硬化病灶的巨噬细胞浸润强度显著更高，支架内再狭窄病灶则显著更低。
【研究结论】通过冠状动脉OCT成像分析可见，新发动脉粥样硬化、支架内再狭窄及支架内新生动脉粥样硬化三类病灶的炎症表型存在显著差异。