NPPB and pulmonary arterial hypertension: BNP and NT-proBNP, alone or in combination with other surrogates of outcome measures/risk assessment tools, remain the most validated and widely used prognostic biomarkers in routine clinical practice of PAH.5, 33, 41, 51, 55, 69, 76, 77, 78, 96 In a posthoc analysis of the Prostacyclin [PGI2] Receptor Agonist In Pulmonary Arterial Hypertension (GRIPHON) trial, Chen et al confirmed the highly prognostic potential of NT-proBNP cut-off levels (<300 ng/liter, 300-1,400 ng/liter, and >1,400 ng/liter) used in the 3 strata ESC/ERS risk assessment strategy, at baseline and follow-up.77