Using the above diagnostic criteria, Jankowska et al. recently documented a 37% prevalence of ID among 546 patients with chronic systolic HF [13] and identified female gender, advanced disease (New York Heart Association class, and elevated plasma N-terminal pro-B-type natriuretic peptide (NT-proBNP) and serum high-sensitivity C-reactive protein levels as independent predictors of a higher likelihood of ID in a relatively young and predominantly male HF population. Here, NPPB is linked to hydrops fetalis.