NPPB and hydrops fetalis: Compared with non-HF patients, patients with HFpEF were more often female (44.6% versus 28.0%; P < 0.001) and had significantly greater maximal wall thickness (24 mm versus 22 mm; P < 0.001), higher maximal left ventricular outflow tract gradient (64 mmHg versus 25 mmHg, P < 0.001), higher NT-proBNP concentrations (1807.0 pg/mL versus 536.8 pg/mL; P < 0.001) and higher proportion of atrial fibrillation (27.3% vs. 13.5%; P < 0.001).