The Relationship between Serum Pro‐Brain Natriuretic Peptide (Pro‐BNP) Levels and Pulmonary Arterial Hypertension (PAH) in Patients with Limited Scleroderma

Introduction: Pulmonary arterial hypertension (PAH) is a late progressive sclerodermarelated complication, which can lead to right heart failure and cor pulmonale. Given that cardiac catheterization is a diagnostic method of choice for PAH, and considering the high risks of this method, the purpose of this study was to evaluate the relationship between serum Pro- Brain natriuretic peptide (Pro-BNP) Levels and PAH in patients with limited scleroderma. Materials and Methods: In this cross sectional study , during June 2011- Dec 2013, referring patients to two major educational hospitals, Mashhad- Iran, with scleroderma, who were afflicted with the disease for at least two years (or more), were enrolled in the study if they met the inclusion and exclusion criteria. All the patients underwent echocardiography to determine the pulmonary artery pressure (PAP). Afterwards, the subjects were referred to a lung center for performing body plethysmography, carbon monoxide diffusing capacity (DLCO), and 6- minute walk test (6MWT). Pro-BNP Serum level was determined using flourescent immune assay method. Results: The present study included 20 patients (18 female subjects) with the mean age of 43.28±9.56 yrs, and the mean pro-BNP level of 138 pg/ml. The logarithmic correlation between PAP values, Forced Vital Capacity /DLCO ratio, and pro-BNP level, which was measured using Pearsonʹs correlation coefficient, showed a significant association among these variables( respectively, r=0.76, P?0.001; r=0.677, P=0.011). Moreover, the DLCO decrease was associated with increasing pro-BNP level, though this relationship was not significant. Conclusion: This study showed that there was a significant relationship between the serum levels of pro-BNP marker and increased PAP in the echocardiography, DLCO reduction, and FVC/DLCO increase. In fact, this serum marker can be used in patients with systemic scleroderma (SSc) to evaluate the status of PAH.