Chin KM, et al. - Researchers performed this post hoc analysis of the GRIPHON trial (Prostacyclin Receptor Agonist In Pulmonary Arterial Hypertension) to ascertain the prognostic ability of N-terminal pro brain natriuretic peptide (NT-proBNP) thresholds in pulmonary arterial hypertension (PAH) as well as to assess the response to selexipag according to these thresholds. The patients were randomized to selexipag or placebo in GRIPHON trial. In this analysis, patients were divided into low, medium, and high NT-proBNP subgroups using two independent sets of thresholds. Findings confirmed the prognostic value of NT-proBNP levels in PAH. A link between NT-proBNP level and treatment response was evident for the first time in this study. The relevance of the low, medium, and high NT-proBNP divisions as a component of the multiparametric risk evaluation approach described in the European Society of Cardiology/European Respiratory Society guidelines for the management of PAH patients was supported in this study using two similar sets of thresholds.