Usefulness of Serial N-Terminal Pro–B-Type Natriuretic Peptide Measurements for Determining Prognosis in Patients With Pulmonary Arterial Hypertension

Previous studies have shown the prognostic benefit of N-terminal pro–brain natriuretic peptide (NT–pro-BNP) in pulmonary arterial hypertension (PAH) at time of diagnosis. However, there are only limited data on the clinical utility of serial measurements of the inactive peptide NT–pro-BNP in PAH. This study examined the value of serial NT–pro-BNP measurements in predicting prognosis PAH. We retrospectively analyzed all available NT–pro-BNP plasma samples in 198 patients who were diagnosed with World Health Organization group I PAH from January 2002 through January 2009. At time of diagnosis median NT–pro-BNP levels were significantly different between survivors (610 pg/ml, range 6 to 8,714) and nonsurvivors (2,609 pg/ml, range 28 to 9,828, p <0.001). In addition, NT–pro-BNP was significantly associated (p <0.001) with other parameters of disease severity (6-minute walking distance, functional class). Receiver operating curve analysis identified ≥1,256 pg/ml as the optimal NT–pro-BNP cutoff for predicting mortality at time of diagnosis. Serial measurements allowed calculation of baseline NT–pro-BNP (i.e., intercept obtained by back-extrapolation of concentration–time graph), providing a better discrimination between survivors and nonsurvivors than NT–pro-BNP at time of diagnosis alone (p = 0.010). Furthermore, a decrease of NT–pro-BNP of >15%/year was associated with survival. In conclusion, a serum NT–pro-BNP level ≥1,256 pg/ml at time of diagnosis identifies poor outcome in patients with PAH. In addition, a decrease in NT–pro-BNP of >15%/year is associated with survival in PAH.