Disproportionate Elevation of NT-proBNP in Scleroderma- Related Pulmonary Hypertension

Objective: N-terminal pro-brain natriuretic peptide (NT-proBNP) is a marker of neurohormonal activation that is useful in the diagnosis and prognosis of various forms of pulmonary arterial hypertension (PAH). We sought to characterize and compare NTproBNP in a cohort of PAH-related to scleroderma (PAH-SSc) and idiopathic PAH (IPAH) patients. . Published on July 30, 2009 as doi: 10.1183/09031936.00074309 ERJ Express Copyright 2009 by the European Respiratory Society. 2 Methods: NT-proBNP levels, collected from PAH-SSc and IPAH patients followed prospectively, were compared and correlated with hemodynamic variables. Cox proportional hazard models were created to assess the predictive value of NT-proBNP. Results: Ninety-eight patients (55 PAH-SSc, 43 IPAH) were included. Hemodynamics were similar, except for lower mPAP in PAH-SSc. NT-proBNP levels were significantly higher in PAH-SSc (3419±3784 vs. 1393±1633 pg/mL, p<0.01), and were more closely related to hemodynamics in PAH-SSc than IPAH. Twenty-eight patients died. NTproBNP predicted survival (HR 3.18; p<0.01) in the overall cohort; however when stratified by group, predicted survival only in PAH-SSc (HR 3.07, p<0.01 vs. 2.02, p=0.29 in IPAH). Conclusions: This is the first description showing NT-proBNP levels are 1) significantly higher in PAH-SSc than IPAH despite less severe hemodynamic perturbations, and 2) stronger predictors of survival in PAH-SSc, suggesting that neurohormonal regulation may differ between PAH-SSc and IPAH. Future studies to define pertinent mechanisms are warranted. Introduction Pulmonary arterial hypertension (PAH) is a chronic disease of the pulmonary vasculature that leads to right heart failure and death. PAH affects approximately 814% of patients with underlying systemic sclerosis (SSc) and is associated with a worse prognosis as compared to patients with other forms of PAH. The reasons for these differences in survival are unclear, but may be related to several factors.