Coronary plaque instability is associated with inflammatory activity of visceral adipose tissue and carotid artery: a prospective pilot F-18 FDG PET/CT study

Objectives: Dysfunctional Visceral adipose tissue (VAT) secretes pro-inflammatory cytokines and promotes inflammatory cell infiltration into VAT thereby boosting insulin resistance and systemic inflammation which eventually lead to increased risk of cardiovascular disease (CVD). F-18 FDG PET/CT is well known to reflect the inflammatory activity of classically activated (M1) macrophage. We hypothesized that F-18 FDG PET/CT could reflect the inflammatory activity of dysfunctional VAT and carotid artery which were associated with coronary plaque instability.

Methods: A total of 90 participants were enrolled in this prospective study. F-18 FDG PET/CT was performed in 32 participants with acute myocardial infarction (AMI) within a week of disease onset, 33 participants with stable coronary artery disease (CAD), and 25 control subjects. Maximum standardized uptake value (SUVmax) was calculated in VAT, subcutaneous adipose tissue (SAT), spleen, and bone marrow (BM). Target-to-background ratio (TBR) was calculated in right carotid artery and right jugular vein.

Results: The SUVmax of VAT and the TBR of right carotid artery were highest in patients with AMI, intermediate in patient with stable CAD, and lowest in control subjects. Systemic inflammation surrogate markers such as high-sensitivity C-reactive protein, spleen SUVmax were also showed similar pattern like the SUVmax of VAT and the TBR of right carotid artery. Furthermore, multiple linear regression analysis showed that the SUVmax of VAT and spleen SUVmax were independently associated with the TBR of right carotid artery.

Conclusions: F-18 FDG PET/CT could reflect the synchronized systemic inflammation in VAT and carotid artery which could affect the coronary artery instability. Furthermore, our findings offer clinical insights into risk stratification, monitoring of therapy, and physiological changes in the development of CAD.