Subsequent Development of Fibroatheromas With Inflamed Fibrous Caps Can Be Predicted by Intracoronary Near Infrared Spectroscopy

Abstract

Objective-To prospectively evaluate whether the development of fibroatheromas exhibiting features of potential instability can be detected and predicted by serial invasive imaging. Methods and Results-Multivessel intravascular ultrasound and near infrared spectroscopy (NIRS) were performed in diabetic/hypercholesterolemic pigs 3, 6, and 9 months after induction. Animals were euthanized at 9 months and histological/immunohistochemical evaluation of the arteries was performed (n=304 arterial segments). Intravascular ultrasound demonstrated, over time, a progressive increase in plaque + media and necrotic core areas and positive vascular remodeling. By histology, NIRS+ lesions were significantly more likely to be a high-risk fibroatheroma (P=0.0001) containing larger plaque (P<0.0001) and necrotic core areas (P<0.0019) and thinner fibrous caps (P=0.04). NIRS + fibroatheromas possessed a greater concentration of inflammatory cells demonstrating protease activity (P=0.006), and proliferating (P=0.016), and apoptotic cells (P=0.04) within the fibrous cap. Eighty-eight percent of NIRS+ lesions at 3 and 6 months subsequently developed into a fibroatheroma at 9 months (P<0.01). By multivariate analysis NIRS positivity at 6 months predicted the subsequent presence of a fibroatheroma at 9 months (P=0.005; odds ratio, 2.71). Conclusion-The

Porcine Models of Accelerated Coronary Atherosclerosis: Role of Diabetes Mellitus and Hypercholesterolemia

“…Using Near Infrared Spectroscopy (NIRS) and IVUS imaging, obtained at 3, 6, and 9 months after DM/HC induction, Patel et al [17] demonstrated that the combination of NIRS and IVUS could detect the presence of a fibroatheroma and importantly predict the future development of fibroatheromas. The early and persistent accumulation of lipid within the arterial wall of coronary arteries led to the subsequent development of fibroatheromas, often demonstrating increased inflammation in the plaque and within the fibrous cap as well as thinned fibrous caps; markers of high-risk lesions.…”

Evaluation of human coronary vasodilator function predicts future coronary atheroma progression

“…Indeed, pathology studies indicated that plaque growth predominantly occurs as a result of recurrent events of plaque disruption followed by healing28; a downstream process to necrotic core formation which is characterised by non-resolving inflammation, macrophage infiltration and smooth muscle cells apoptosis 29. Incidentally, NIRS-positive lesions are not only known to contain rich free cholesterol monohydrate and cholesterol ester but also heightened inflammatory and apoptotic cellular activity within the plaque and fibrous cap,30 a marker of a more ‘aggressive’ atherosclerotic disease activity.…”

Near-Infrared Spectroscopy (NIRS): A Novel Tool for Intravascular Coronary Imaging

“…The thin-cap fibroatheroma (TCFA) is believed to be the precursor lesion of plaque rupture, although there is a lack of prospective robust evidence in the literature [15,89]. A prospective animal study conducted in an atherosclerotic and diabetic pig model showed that NIRS-IVUS imaging can detect and predict the future development of inflamed fibroatheromas with subsequent validation against postmortem histology [90]. The features of rupture-prone plaques included thinned fibrous cap, increased plaque and necrotic core areas, increased concentration of activated inflammatory cells, and the presence of apoptotic and proliferating cells within the fibrous cap [90].…”

“…A prospective animal study conducted in an atherosclerotic and diabetic pig model showed that NIRS-IVUS imaging can detect and predict the future development of inflamed fibroatheromas with subsequent validation against postmortem histology [90]. The features of rupture-prone plaques included thinned fibrous cap, increased plaque and necrotic core areas, increased concentration of activated inflammatory cells, and the presence of apoptotic and proliferating cells within the fibrous cap [90]. An autopsy study of 103 coronary arteries from 56 autopsied hearts, aiming to assess grayscale IVUS and NIRS detection of histological fibroatheroma (FA), with histology validation as the gold standard, showed that both superficial IVUS attenuation and NIRS-LCP had a similar high specificity of approximately 95% in detecting FAs, however IVUS showed a low sensitivity (36% vs.…”