ADRB2 and hydrops fetalis: We successfully replicated the ADRB2 Arg16Gly site-dependent heterogeneity in prognosis of HF in this independent cohort, and the result showed that in the natural state without treatment of β-blockers, patients carrying G allele (AG/GG genotype) had worse prognosis compared with patients who are AA homozygous (adjusted HR, 2.09; 95% CI, 1.06−4.12; P = 0.034 for AG/GG versus AA; Supplementary Table S11).