N-terminal probrain natriuretic peptide as a biochemical marker in the evaluation of bosentan treatment in systemic-sclerosis-related pulmonary arterial hypertension.

The purpose of our study was to investigate the effect of bosentan treatment on surrogate markers in patients with systemic-sclerosis-related pulmonary arterial hypertension (SScPAH). We studied ten SScPAH patients (nine female, median age 58 years, median duration of disease 9 years). Six-minute walk test (SMWT) and plasma N-terminal probrain natriuretic peptide (NT-proBNP) levels were recorded from patients at baseline and after 20 weeks under bosentan treatment. Wilcoxon paired signed rank test was applied in order to compare NT-proBNP levels and SMWT at baseline and week 20. At week 20, NT-proBNP levels were decreased from a median of 474 fmol/ml (range, 212-1407 fmol/ml) at baseline to 238 fmol/ml (range, 198-335 fmol/ml; p=0.002). Mean SMWT distance increased from a baseline median value of 323 m (range, 224-368 m) to 372 m (range, 232-530 m), representing a nonsignificant increase. Our results suggest that NT-proBNP is a biochemical surrogate marker, which could be used to evaluate the effects of bosentan or other vasodilation therapy in SScPAH.