The results showed that there was no association between higher FGF21 levels and a composite of death or HF readmission among patients with HF, although there was a statistically significant trend (HR: 1.57, 95% CI: 0.99–2.48, P > 0.05, I2 = 95%, random-effect model; Figure 2C). Here, FGF21 is linked to hydrops fetalis.