We found that the miR-487b mimic group showed downregulated IL-33 and ST2 as well as upregulated miR-487b, and less cell apoptosis, inflammatory responses of myocarditis, and fibrosis were observed in this group, suggesting miR-487b alleviates CHF through inhibition of the IL-33 and ST2 signaling pathway. Here, IL33 is linked to myocarditis.