Inflammatory cytokines in chronic heart failure: Interleukin-8 is associated with adverse outcome. Results from CORONA

Aim: We investigated the ability of prototypical inflammatory cytokines to predict clinical outcomes in a large population of patients with chronic systolic heart failure (HF). Methods and results: Serum levels of tumour necrosis factor-α (TNF-α), soluble TNF receptors type I and II (sTNF-RI and sTNF-RII), and the chemokines monocyte chemoattractant protein-1 (MCP-1) and interleukin-8 (IL-8) were analysed in 1464 patients with chronic ischaemic systolic HF in the CORONA study, aged ≥ 60 years, in NYHA class II–IV, and related to the primary endpoint (n = 320), as well as any coronary event (n = 255), all-cause mortality (n = 329), cardiovascular (CV) mortality (n = 268), and the composite endpoint hospitalization from worsening heart failure (WHF) or CV mortality (n = 547). TNF-α, sTNF-RI, sTNF-RII, and IL-8, but not MCP-1, were independent predictors of all endpoints except the coronary endpoint in multivariable models including conventional clinical variables. After further adjustment for estimated glomerular filtration rate, the ApoB/ApoA-1 ratio, NT-proBNP, and high-sensitivity C-reactive protein, only IL-8 remained a significant predictor of all endpoints (except the coronary endpoint), while sTNF- RI remained independently associated with CV mortality. Adding IL-8 to the full model led to a significant improvement in net reclassification for all-cause mortality and CV hospitalization, but only a borderline significant improvement for the primary endpoint, CV mortality, and the composite endpoint WHF hospitalization or CV mortality. Conclusion: Our study supports a relationship between IL-8 and outcomes in patients with chronic HF. However, the clinical usefulness of IL-8 as a biomarker in an unselected HF population is at present unclear.