Compared with those prior syntheses, our meta-analysis has distinctive features: (i) we included only prospective cohort studies of HF populations (not mixed CVD); (ii) we simultaneously examined IL-6, hs-CRP and NLR in one analytical framework, facilitating direct comparison of prognostic strength; and (iii) we conducted detailed subgroup and sensitivity analyses (including by ejection fraction phenotype, region, biomarker assay method). This evidence concerns the gene IL6 and hydrops fetalis.