The aim of this study was to identify histological features that correlate with terms commonly used to describe optical coherence tomographic (OCT) and optical frequency-domain imaging (OFDI) images of stented vessels, by means of a histopathological validation study using stented human coronary arteries.
Background
OCT imaging and OFDI are used to evaluate vascular responses to stent implantation. Descriptive terms such as “peristrut low attenuation” and “heterogeneous” have been used to describe neointimal characteristics that may have clinical relevance. However, only limited histopathological correlations are available.
Methods
Using the CVPath stent registry, 19 cases were identified in whom implantation duration was >30 days and OCT imaging or OFDI and histological findings were available. Consecutive OCT or OFDI frames (n = 1,063) of stented coronary arteries were categorized according to their predominant imaging features in 1-mm intervals. Coregistration of OCT or OFDI frames and histopathological cross sections was performed in 111 frames.
Results
Seven distinct OCT or OFDI patterns were found: homogenous (45%), layered (15%), high intensity with high attenuation (14%), intraluminal protruding masses (8%), peristrut low attenuation (7%), heterogeneous (2%), and honeycomb (1%). Histopathologically, the homogenous pattern correlated most often with smooth muscle cells within collagenous/proteoglycan matrix and less often with organized thrombus. The layered pattern correlated with healed neointimal rupture or erosion, peristrut neovascularization, or smooth muscle cells within collagen/proteoglycan matrix. High intensity with high attenuation correlated with superficial macrophage accumulation in the majority of cases, but with other histological findings in 30% of cases. The diagnostic accuracy was greater in restenotic lesions. The only OCT or OFDI finding that had a single histological feature was the honeycomb pattern.
Conclusions
This study suggests a lack of correlation between OCT image patterns and distinct histological tissue characteristics.
CVPath Institute, a private, nonprofit research organization in Gaithersburg, Maryland, provided full support for this study. CVPath Institute has research grants from Abbott Vascular, Atrium Medical, Boston Scientific, Biosensors International, Cordis/Johnson & Johnson, Medtronic CardioVascular, OrbusNeich Medical, and Terumo. Dr. Joner is a consultant for Biotronik; receives grant support from the European Commission; and has received speaking honoraria from Abbott Vascular, Biotronik, Boston Scientific, and OrbusNeiche. Dr. Virmani has speaking engagements with Merck; receives honoraria from Abbott Vascular, Boston Scientific, Lutonix, Medtronic, and Terumo; and is a consultant for 480 Biomedical, Abbott Vascular, Medtronic, and W.L. Gore. Dr. Finn has sponsored research agreements with Boston Scientific and Medtronic CardioVascular; and is an advisory board member for Medtronic CardioVascular. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
