Pericoronary fat attenuation and its association with atherosclerosis in rheumatoid arthritis compared with controls: a cross-sectional study.

Mean pericoronary adipose tissue attenuation (PCATa) was higher in RA patients than controls after adjustment for age, sex, cardiovascular risk factors, and epicardial adipose tissue volume.

• The study included 147 patients with RA and 118 age-matched and sex-matched controls with complete coronary CT angiography data.
• Mean PCATa was higher in RA than controls (B=0.35, 95% CI 0.12 to 0.58).
• Models were adjusted for age, sex, cardiovascular risk factors, and epicardial adipose tissue volume.
• PCATa and plaque counts were assessed at a single cross-sectional time point.

Artery-specific PCATa around the right coronary artery (RCA) and left circumflex (LCx) artery were both significantly higher in RA than controls.

• RCA-PCATa was higher in RA than controls (B=0.39, 95% CI 0.14 to 0.63).
• LCx-PCATa was higher in RA than controls (B=0.25, 95% CI 0.03 to 0.48).
• Both associations remained significant after adjustment for cardiovascular risk factors and epicardial adipose tissue volume.

Mean PCATa was higher in males than females across the study population.

• The sex difference in mean PCATa was statistically significant (p<0.01).
• This finding applied to the overall cohort of RA patients and controls combined.

Age and dyslipidaemia influenced PCATa differently in RA patients compared with controls.

• The interaction p-value for age was 0.032, indicating a differential effect of age on PCATa between RA and controls.
• The interaction p-value for dyslipidaemia was 0.021, indicating a differential effect of dyslipidaemia on PCATa between RA and controls.

Mean PCATa and LCx-PCATa were associated with total and mixed plaque counts in RA but not in controls.

• The interaction p-value for the association of mean PCATa with plaque counts between RA and controls was 0.040.
• The interaction p-value for the association of LCx-PCATa with plaque counts between RA and controls was 0.021.
• Associations were observed for total plaque counts and mixed plaque counts specifically.
• Non-calcified and calcified plaque count associations were not specifically highlighted as significant interaction findings.

Per-artery PCATa did not differ between RA and controls in participants without atherosclerosis, but PCATa around plaque-free LCx and RCA vessels was higher in RA than controls among participants with atherosclerosis.

• Among participants with atherosclerosis, PCATa around plaque-free LCx and RCA vessels was higher in RA than controls (p<0.05 for both).
• This difference was not observed in participants without any atherosclerosis, suggesting a systemic inflammatory signal in RA patients who already have plaque elsewhere.
• This finding implies that vascular inflammation in RA extends beyond plaque-containing segments when coronary atherosclerosis is present.