Serum N-Terminal Brain Natriuretic Peptide as a Prognostic Parameter in Patients With Pulmonary Hypertension

Study objectivesBaseline prognostic assessment in patients with pulmonary hypertension (PH) may help in the selection of treatment. High plasma levels of natriuretic peptide type B have been reported in patients with right ventricular (RV) dysfunction and suggest poor prognosis in patients with idiopathic pulmonary arterial hypertension (IPAH). We prospectively assessed the correlation of N-terminal brain natriuretic peptide (NT-proBNP) with echocardiographic and hemodynamic indexes of RV function as well as with baseline functional status and long-term survival of PH patients.Patients and designFifty-five consecutive patients with a mean (± SD) age of 41 ± 15 years and severe PH (including 36 patients with IPAH) were followed up for up to 36 months. Serum samples for NT-proBNP were secured, and 6-min walk test (6 MWT), RV catheterization, and echocardiography were all performed on the same day, before the introduction of targeted treatment.ResultsThe median baseline serum NT-proBNP concentration was 1,674 pg/mL (range, 51 to 10,951 pg/mL). NT-proBNP concentration correlated with 6MWT distance (r = 0.6 p < 0.001), cardiac index, pulmonary vascular resistance, and right atrial pressure (RAP), but not with pulmonary arterial pressure. NT-proBNP levels were also related to the ratio of the diastolic area of the RV and the LV, and to pericardial effusion during echocardiography. Receiver operating characteristic analysis identified ≥ 1,400 pg/mL as the best NT-proBNP threshold predicting fatal outcome for the entire study group as well as for IPAH patients (sensitivity, 88% and 100%, respectively; specificity, 53% and 56%, respectively). In multivariate analysis, NT-proBNP, troponin T, and RAP were identified as independent factors for poor prognosis for the entire study group, while only NT-proBNP and RAP were identified as markers for poor prognosis in the IPAH subgroup.ConclusionsNT-proBNP level is related to the right heart morphology and dysfunction in PH patients. A serum NT-proBNP level of ≥ 1,400 pg/mL was found to be useful in identifying patients with poor long-term prognosis both in the whole studied group and in the IPAH subgroup.