NPPB and hydrops fetalis: In an attempt to enrich the study cohort with patients who had a high likelihood of reaching at least one of the co-primary endpoints, inclusion criteria allowed only patients with more advanced disease as mirrored by a requirement of diuretic treatment and relatively high serum levels of N-terminal prohormone of brain natriuretic peptide (NT-proBNP), if recent hospitalization for HF was absent.