NPPB and chronic obstructive pulmonary disease: Elevated levels (Table 1) (BNP ≥ 35 pg/mL, NT-proBNP ≥ 125 pg/mL—for ambulatory patients; BNP ≥ 100 pg/mL, NT-proBNP ≥ 300 pg/mL—in hospitalized patients with acute decompensation) strongly suggest a cardiac etiology [16], although these markers can also be mildly raised in patients with COPD, with increased levels observed in approximately 50% of cases, particularly during exacerbations or in the presence of cor pulmonale (Figure 3) [26,70,71].