Although smoking history was common, chronic obstructive pulmonary disease was formally diagnosed in only one patient (LVEF 30%, NTproBNP 344 pg/mL), and available pulmonary function tests in others did not support significant obstructive lung disease as the primary cause of exertional dyspnoea (see Supplementary material, Supplementary material online, Table S1). Here, NPPB is linked to Airway obstruction.