Abstract 21080: Future Development of Fibroatheromas Can be Predicted by NIRS: Insights From the DM/HC Pig Model.
Introduction: Fibroatheromas are the pathologic cause of acute coronary syndromes and ischemic sudden death. Near Infrared Spectroscopy (NIRS) detects lipid concentration in the arterial wall and Intravascular Ultrasound (IVUS) identifies echolucent necrotic cores (NC) and vascular remodeling. We hypothesized that detection of increased lipid in the coronary vascular wall would predict future development and progression of high-risk fibroatheromas, containing larger necrotic cores.
Methods: Diabetes (DM) and hypercholesterolemia (HC) were induced in 19 male Yorkshire pigs. Coronary angiography, IVUS and NIRS of all 3 arteries were performed at 3, 6 and 9 months thereafter. During the study period cholesterol levels remained stable (511±64 mg/dl). Animals were sacrificed at 9 months and histological sections were obtained. On IVUS, atheroma (plaque + media) and echolucent (NC) areas were measured. NIRS was considered positive for lipid when block chemograms showed yellow or orange blocks. The results of IVUS and NIRS were compared to histological sections.
Results: IVUS analysis showed progression of plaque + media and variable development of echolucent NC areas over time. NIRS positivity at 3 month predicted greater plaque + media area by IVUS at 6 (5.6±2.7 vs 4.5±2.5 mm2, P<0.01) and 9 months (10.9±8.5 vs 7.6±6.7 mm2, P<0.01). Furthermore, 3 and 6 month NIRS positive sections exhibited larger mean NC area at 6 (p=0.09) and 9 months (p<0.01) respectively. Histology confirmed this finding as 3 and 6 month NIRS positive areas subsequently developed into larger plaques (p<0.01) and greater NC areas (p<0.01, Figure). Moreover, 82% of NIRS positive sections at 3 and 6 month compared to only 28% of NIRS negative sections developed into fibroatheroma on histology (p<0.01).
Conclusions: Early detection of lipid within the arterial wall predicted the subsequent development of high-risk coronary fibroatheromas with greater plaque area and larger necrotic core area.
- © 2010 by American Heart Association, Inc.