Pericoronary adipose tissue CT attenuation and its association with serum levels of atherosclerosis-relevant inflammatory mediators, coronary calcification and major adverse cardiac events

Background: Increased attenuation of pericoronary adipose tissue (PCAT) around the right coronary artery (RCA) derived from coronary CTA might detect coronary inflammation. We investigated a potential association between RCA PCAT attenuation and serum levels of atherosclerosis-relevant cytokines and MACE (coronary revascularization, myocardial infarction and/or cardiac death). Methods: Blood samples of 293 clinically stable individuals (59.0 +/- 9.8 years, 69% males) were analyzed for atherosclerosis-relevant cytokines including interleukin (IL)-2, IL-4, IL-6, IL-7, IL-8, IL-10, IL-13, IL-15, IL-17, TNF-a, IP-10, CRP, MCP-1, MIP-1a, Eotaxin and GM-CSF. Subjects also underwent coronary calcium scoring (CCS) followed by CTA. PCAT CT attenuation was measured around the RCA using semi-automated software. Increased RCA PCAT attenuation was defined as PCAT attenuation above the 75th percentile (>-73.5 HU). To assess MACE, 232 individuals were followed for a mean duration of 9.6 +/- 2.1 years. Results: In patients with increased RCA PCAT attenuation the serum levels of MCP-1 were increased (p < 0.01), whereas levels of anti-inflammatory mediators IL-4 and-13 were significantly reduced (each p < 0.05). Adipocytokine MCP-1 (r = 0.23, p < 0.01) and pro-inflammatory mediator IL-7 (r = 0.12, p = 0.04) showed a mild positive correlation with RCA PCAT attenuation, whereas anti-inflammatory mediators Il-4,-10 and-13 correlated inversely (each r <-0.12, each p < 0.05). 40/232 patients experienced MACE during follow-up. In multivariable Cox regression analysis increased RCA PCAT attenuation was shown to be an independent predictor of MACE (HR 2.01, p = 0.044). Conclusions: Increased RCA PCAT CT attenuation shows a weak association with serum levels of selected atherosclerosis-relevant inflammatory biomarkers. Increased RCA PCAT attenuation is an independent predictor of MACE and may potentially guide future prevention strategies in stable patients.

Automated summary

The study found that increased attenuation of pericoronary adipose tissue (PCAT) around the right coronary artery (RCA) was associated with reduced levels of interleukin-4 and-13, and increased levels of Monocyte Chemoattractant Protein-1 (MCP-1). Increased RCA PCAT attenuation was identified as an independent predictor of major adverse cardiovascular events (MACE).