Inflammatory phenotype by OCT coronary imaging: specific features among de novo lesions, in-stent neointima, and in-stent neo-atherosclerosis

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 mu m(3)/ 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.