Compared to the serum levels of PCSK9 prior to HF induction by isoproterenol, the levels of PCSK9 were significantly elevated 14 days after HF induction (n = 6 rats, 178.3 ± 20.8 versus 272.2 ± 20.5 ng/mL, p < 0.01). This evidence concerns the gene PCSK9 and hydrops fetalis.