Matsumoto S, Nakazawa G, Ohno Y, et al. - Researchers sought to characterize the differential regulation of circulating atrial natriuretic peptide (ANP) as well as the efficacy of exogenous ANP (carperitide) in patients experiencing acute heart failure (HF), particularly HF with preserved ejection fraction (HFpEF). In 113 patients with acute HF who were split into two groups [HFpEF vs HFrEF(HF with reduced ejection fraction)], serum ANP concentrations prior to treatment and the diuretic impact of 0.0125 μg/kg/min of carperitide alone for the first 6 h were prospectively assessed. An inverse link was identified between ANP levels and the diuretic effect of exogenous ANP. Lower ANP concentrations and a greater diuretic effect of exogenous ANP were detected in patients with HFpEF vs those with HFrEF. Overall, it was inferred that patients suffering from HFpEF might have an aspect of ANP deficiency and represent a promising treatment target for modulating circulating ANP.