Spironolactone (Aldactone), an aldosterone antagonist, is recommended in the HF guidelines because it improves the prognosis of HFrEF patients.[33] In the Aldo-DHF trial,[24] spironolactone improved the LV dilations and the N-terminal pro-BNP levels in patients with HFpEF and it significantly decreased HF hospitalizations in the Treatment of Preserved Cardiac Function Heart Failure with an Aldosterone Antagonist (TOPCAT) study.[34] One of the physiological conditions of HFpEF is that due to a sharp increase in left atrial pressure during exercise, pulmonary edema occur can occur. Here, NPPB is linked to hydrops fetalis.