Abstract 2198: The Combination of Serum Inflammatory Markers (CRP and PAI-1) and Positron Emission Tomography Can Identify Vulnerable Plaques Leading to Arterial Thrombosis.
Background: Serum inflammatory markers are associated with risk for cardiovascular events. Also, it has been shown that Fluorine-18 fluorodeoxyglucose (FDG) uptake in plaques is proportional to the degree of inflammation and macrophage density. We hypothesized that the combination of inflammatory markers and high FDG uptake as manifested by increased Standardized Uptake Value (SUV) can identify Vulnerable Plaque leading to thrombosis.
Methods: Twenty NZW rabbits were made atherosclerotic by cholesterol feeding (6 – 8 months), 14 were pharmacologically triggered for thrombosis. Positron Emission Tomography (PET) scans were performed 2 hr after injection of 2 mci of FDG at baseline, during cholesterol feeding and after triggering. Maximal SUV was averaged over the aorta. CRP and PAI-1 levels were obtained simultaneously. Thrombi were identified at post mortem.
Results: Mean aortic diameter was 2.8 mm. SUV increased by 64% with cholesterol feeding and 115% with thrombosis. PAI-1 and CRP increased by 38 and 200 fold respectively with wide variability depending on the time of collection and triggering (Figure⇓). PAI-1 was highest in the group with thrombosis.
Conclusion: CRP and PAI-1 increased significantly during atherosclerosis. FDG uptake and hence plaque inflammation increased proportionally with the duration of cholesterol feeding. Thrombosis was preceded with increasing plaque FDG uptake. Therefore FDG-PET can detect inflamed arteries accurately and localize the inflamed segments. Our study implies the feasibility to use the elevation of CRP and PAI-1 to identify vulnerable patients and FDG uptake to diagnose and localize Vulnerable Plaques to predict thrombosis.