Subclinical coronary artery calcification is associated with future inflammatory conditions in the multi-ethnic study of atherosclerosis

Background: Inflammation is integral to cardiovascular disease (CVD). We previously defined Chronic Inflammatory-Related Disease (ChrIRD) as a collective of various non-cardiovascular and non-cancer conditions with a common basis of inflammation. ChrIRD has a bidirectional association with CVD. As both coronary artery calcification (CAC) and ChrIRD have inflammatory associations, we hypothesize that baseline CAC predicts future ChrIRD. Methods: We studied Multi-Ethnic Study of Atherosclerosis participants free of overt CVD at baseline. ChrIRD was determined based on ICD codes for hospitalizations and deaths. All participants underwent baseline ECG-gated non-contrast CT with Agatston scoring for CAC quantification. We performed proportional hazards regression to identify associations between baseline CAC, baseline inflammatory markers, and future ChrIRD. Results: Participants (n = 6791) had mean age 62 ± 10 years, with 47 % men, 38 % White, 28 % Black, 22 % Hispanic, and 12 % Chinese race/ethnicity. During 18-year follow-up, ChrIRD occurred in 16 %. Increasing baseline Agatston score was associated with increased risk for future ChrIRD compared to baseline Agatston score 0. Agatston score (HR per SD 1.20) was as strong a predictor of ChrIRD as baseline interleukin-6 (IL-6) levels (HR per SD 1.21). Conclusions: Increasing baseline CAC among individuals free of overt CVD or other significant illness is associated with progressive risk of future ChrIRD. Agatston score was as predictive as IL-6. These findings support CAC as a subclinical marker of systemic inflammation, not limited to the coronary vasculature alone.