Subsequent Development of Fibroatheromas With Inflamed Fibrous Caps Can Be Predicted by Intracoronary Near Infrared Spectroscopy
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), 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 future development of inflamed fibroatheromas with thinner fibrous caps, greater plaque, and necrotic core areas, characteristics of increased plaque instability were detected by intravascular ultrasound/NIRS imaging.
- Received July 11, 2012.
- Accepted November 29, 2012.
- © 2013 American Heart Association, Inc.