NPPB and chronic obstructive pulmonary disease: In the present study, we demonstrated that anticholinergic bronchodilator therapy decreases the plasma BNP level in patients with HFrEF complicated by COPD, and there was a significant relationship between the percentage decrease of the plasma BNP level and the absolute change of FEV1.0 resulting from tiotropium inhalation (r = −0.68, p < 0.01) in both groups (Figure 4).