In vivo optical coherence tomography imaging and histopathology of healed coronary plaques

The aim of this study was to assess agreement between optical coherence tomography (OCT) and histopathology for healed coronary plaques (HCPs) in human coronary arteries ex vivo, and to evaluate the prevalence and characteristics of HCPs in vivo.

Ex vivo OCT images were co-registered with histopathology in 144 cross-sections with ≥50% stenosis. Of these, 30 randomly selected pairs were employed to define morphological features of OCT for HCPs (OCT-derived HCPs); the remaining 114 pairs were used to evaluate the accuracy of OCT in detecting histologically-defined HCPs. In a clinical study, 60 target lesions from 60 patients with stable ischemic heart disease were divided into 2 groups according to the presence or absence of OCT-derived HCPs. Plaque characteristics were compared between the two groups.

In the autopsy study, an OCT-derived HCP was defined as a plaque with heterogeneous signal-rich layers of different optical signal density. The sensitivity, specificity, positive predictive value, and negative predictive value of OCT-derived HCP to detect histologically-defined HCPs were 81%, 98%, 93%, and 93%, respectively. In the clinical study, 46 (77%) had OCT-derived HCPs. Both microvessels and macrophages were more frequently identified in OCT-derived HCPs compared to their counterparts (43% vs. 0%; p<0.01, 70% vs. 21%; p<0.01, respectively).

An ex vivo OCT image has a good agreement with histology for HCPs detection. HCPs were frequently identified by OCT in target lesions in stable ischemic heart disease patients. OCT may be a useful intracoronary imaging for HCPs detection in vivo.