Читать книгу Interventional Cardiology - Группа авторов - Страница 36

Pathophysiologically, macrophages play a very important role in the development of atherosclerosis and are the predominant inflammatory cell population within the fibrous cap of vulnerable plaques [79]. TCFA manifested by the infiltration of macrophages (average size 20 to 50 μm) has been recognized as contributing to weakening structural integrity of the cap [148–150] and predispose plaques to rupture. They are more frequently found in coronary artery specimens obtained from patients with ACS compared to stable CAD.150 The high contrast and resolution of OCT enables the quantification of macrophages within fibrous caps. OCT visualizes macrophages as signal‐rich, distinct or confluent punctuate regions with heterogeneous backward shadows (Figure 1.5,). Tearney, et al. demonstrated that the OCT‐derived macrophage density of plaque fibrous caps correlated strongly (r=0.84, p<0.0001) with macrophage density quantified histolomorphometrically by CD68 immunoperoxidase staining in the corresponding histological samples [151]. They also showed that macrophage density in the fibrous caps correlated with the circulating white blood cell count, which is used in clinical practice as a marker of systemic inflammation and has been shown to be an independent predictor of cardiovascular events, and presence of TCFA [152]. Thus, OCT has been employed to identify and quantify macrophage infiltration.