NPPB and pulmonary arterial hypertension: The treatment benefit was assessed by analysis of the risk of a first mortality/PAH-related morbidity event (primary endpoint), functional outcomes (6-minute walk distance [6MWD], Borg dyspnea index, World Health Organization functional class [WHO FC], N-terminal prohormone of brain natriuretic peptide [NT-proBNP]), and pharmacoeconomic parameters (PAH-related hospitalizations).