NPPB and atrial fibrillation: Thus, 456 patients with chronic HFrEF (LVEF < 45%) were enrolled (NYHA functional classes II–IV) with an episode of worsening HF within 4 weeks of randomization, defined by symptoms or signs of congestion that required hospitalization or outpatient administration of intravenous (IV) diuretics together with an elevated level of B-natriuretic peptide (BNP) ≥ 300 pg/mL or N-terminal pro-B natriuretic peptide (NT-proBNP ≥ 1000 pg/mL if in sinus rhythm; BNP ≥ 500 pg/mL or NT-proBNP ≥ 1600 pg/mL if in atrial fibrillation) (Table 1) [18].