NPPB and hydrops fetalis: As presented in Supporting Information S5: Table 1, age, gender, ischemic heart disease, hyperlipemia, AFIB, NYHA classification, clinical symptoms of HF, CRP, LAC, hemoglobin, red blood cell, platelet, neutrophil, lymphocyte, monocyte, eosinophil, basophil, BUN, eGFR, sodium, calcium, MB, CTNI, amino‐terminal NT‐proBNP, MR, TR, early‐diastolic velocity (E), TRPG, LVAI, E/e', TAPSE, RVFAC, IVC respiratory change, inotropic agents, beta‐blocker, ACEI, and ARB were potential covariates correlated with all‐cause mortality in patients with HFmrEF.