IL6 and hydrops fetalis: Among patients with prevalent HF, 9 biomarkers remained significant after adjustment for multiplicity; NT-proBNP, BNP, hs-cTnT, renin, angiotensin-converting enzyme 2, growth differentiation factor 15, and interleukin-6 levels were higher in HF with reduced ejection fraction, whereas levels of stem cell factor and leptin were higher in HF with preserved ejection fraction (all <i>P</i><0.05).<h4>Conclusions</h4>Of 268 evaluated biomarkers, this study identified biomarkers representing mechanisms strongly associated with subsequent HF hospitalization.