NPPB and chronic obstructive pulmonary disease: As compared with patients having VA ≥ 80%, those with VA < 80% featured the following statistically significant differences: (a) older age; (b) higher prevalence of NYHA class III-IV, abnormal cardiothoracic ratio, persistent atrial fibrillation, COPD comorbidity, and ventilatory restriction; (c) lower FEV1 and DLCO; (d) higher levels of NT-proBNP.