N-terminal-pro-brain natriuretic peptide as a haemodynamic marker in idiopathic pulmonary arterial hypertension.

Patients with idiopathic pulmonary arterial hypertension usually undergo acute vasodilator tests with nitric oxide (NO) for haemodynamic evaluation and therapeutical planning. The aim of this study was to evaluate the link between the variation of N-terminal (NT)-pro-brain natriuretic peptide (BNP) levels and haemodynamic parameters during the acute vasodilator test. A total of 22 idiopathic pulmonary arterial hypertension patients who underwent acute vasodilator tests were studied. Blood samples were collected at baseline and after 30 and 60 min of NO inhalation. NT-pro-BNP levels were measured in each sample. A receiver-operating characteristic curve was used to evaluate the capability of the NT-pro-BNP level variation during NO inhalation in recognising nonresponders. To distinguish responders from nonresponders, the increase of the NT-pro-BNP (0% as cut-off value) determined a 50% specificity and 100% sensitivity (positive predictive value of 38% and a negative predictive value of 100%). These results suggest that N-terminal-pro-brain natriuretic peptide was able to distinguish nonresponder patients with the acute vasodilator test. N-terminal-pro-brain natriuretic peptide may be an interesting additional biological tool in the evaluation of idiopathic pulmonary arterial hypertension patients.