Association of inflammatory markers and carotid intima-media thickness with the risk of cardiovascular events in high-risk patients.

OBJECTIVE: Both inflammatory markers and carotid intima-media thickness (IMT) are associated with future cardiovascular disease (CVD). We investigated whether inflammatory markers can be predictors for incident CVD independent of carotid IMT in atherosclerotic high-risk patients and evaluated the joint effect of inflammatory markers and IMT in CVD prediction.

METHODS: We performed a prospective cohort study of 770 patients who had one or more atherosclerotic risk factors. Serum high-sensitive C-reactive protein (hsCRP), interleukin (IL)-6, IL-18, and carotid IMT were assessed at baseline and the incidence of CVD was determined.

RESULTS: During 4.3 years of mean follow-up, CVD occurred in 104 patients (14%). In univariate analyses, higher levels of hsCRP, IL-6, and IL-18 were significantly related to an increased risk of CVD. However, only IL-6, but not hsCRP or IL-18, was associated with incident CVD after adjustment for conventional risk factors and carotid IMT (hazard ratio of upper half to lower half, 1.87; 95% confidence interval, 1.20-2.93). Measuring IL-6 level in combination with carotid IMT improves the prediction of incident CVD.

CONCLUSIONS: Elevated IL-6 is associated with the risk of CVD independently of carotid IMT in atherosclerotic high-risk patients.