Markousis-Mavrogenis G, et al. - Researchers identified and characterized the links between interleukin (IL)-6 and clinical features, outcomes, and other inflammatory biomarkers in heart failure (HF). From the BIOSTAT-CHF cohort, they included 2,329 patients (89.4% with a left ventricular ejection fraction [LVEF] ≤ 40%) who underwent IL-6 measurements. All-cause death and HF hospitalization over 2 years was considered to be the primary outcome. The identified independent predictors of elevated IL-6 levels included elevated N-terminal pro-brain natriuretic peptide, procalcitonin and hepcidin, younger age, tumor necrosis factor-α/IL-1-related biomarkers, or having iron deficiency, atrial fibrillation, and LVEF > 40%. The primary outcome, all-cause mortality and cardiovascular, as well as non-cardiovascular mortality, were all independently predicted by IL-6, but it failed to improve differentiation in previously published risk models.