NPPB and pulmonary arterial hypertension: Previous large-scale registry analyses of risk scores have identified improvement of invasive (cardiac index, right atrial pressure, SvO2) and/or non-invasive (FC, 6MWD and brain natriuretic peptide (BNP)/NT-proBNP, vital signs, renal function) variables to be related to long-term outcomes of patients with PAH.34, , –37 In addition, risk scores were used in exploratory analyses of randomised, controlled clinical trials; from these trials, it appeared that they may be sufficiently sensitive to differentiate the treatment effects of an experimental therapy.21,38, –40