Coronary Plaque Instability is Linked with Inflammatory Activity of Multiple Organs Including Carotid Plaques and Visceral Adipose Tissue: A Pilot F-18 FDG PET/CT Study

Abstract

Background: Positron emission tomography (PET) is very useful to determine inflammatory activity in the body including arterial plaque. Although many studies suggested that local and systemic inflammation could affect the arterial plaque instability, there were no direct evidences showing the inflammatory activity of other organs in acute myocardial infarction (AMI) patients. Methods: Whole body combined fluorodeoxyglucose PET/computed tomography was performed in 32 patients with AMI (57±12 years) within a week of disease onset, 33 patients with stable coronary artery disease (CAD) (61±12 years), and 25 control subjects (57±8 years). Maximal standard uptake value (SUV) of the highest regions of interest was calculated in the right carotid artery, bone marrow, liver, visceral (VAT) and subcutaneous adipose tissue (SAT). Results: The SUVs of AMI patients in the carotid artery and other organs except SAT were significantly higher than those of CAD patients or control group with and without adjustment for other covariates, whereas SAT SUVs were not significantly different among three groups. Furthermore, the SUVs of CAD patients in bone marrow, liver, and VAT were also higher than those of control group. In the overall population, hsCRP and the SUVs of all measured organs except SAT were significantly correlated to each other. Conclusions: These findings suggest that coronary plaque instability accompanying other vascular inflammation synchronizes with and might be attributed to increased innate immune surveillance by macrophage resident in different tissues such as VAT and reticuloendothelial system including bone marrow and liver.