NT-proBNP (N-terminal prohorne of brain natriuretic peptide) as an early marker for detection of response to endothelin receptor antagonist in pulmonary arterial hypertension patients

Background Endothelin receptor antagonist (ERA) is well-established for targeted therapy of pulmonary arterial hypertension (PAH). According to the guidelines, comprehensive evaluation of responses to PAH-targeted therapy is recommended 3 to 6 months after treatment onset. Early detection of response to ERA after starting new treatment may be of clinical value to establish next therapeutic plan. Purpose We sought to investigate whether NT-proBNP plays a reliable role for early maker of responses to ERA in PAH patients. Methods Sixty four patients (age >19 years old) with a confirmatory diagnosis of PAH were enrolled who were treated with ERA (bosentan or macitentan) in two tertially PAH experts centers. NT-proBNP measurements were performed at baseline, 1 month and 6 months after ERA treatment. Clinical characteristics including WHO functional class, laboratory test, and echocardiographic results were systematically collected. Result Sixty four patients were finally analyzed who completed the 6 months of follow-up. Etiology of PAH was as follows: idiopathic PAH (n=25), connective tissue disease associated PAH (n=16) and congenital heart disease assocciated PAH (n=24). Mean age was 50±15 years-old and female were predominant (75%). NTproBNP level was changed from 703pg/ml [207–2748] at baseline, 301 pg/ml [126–1314] at 1 month and 297pg/ml [106–901] at 6 months after ERA treatment. Although, NT proBNP level in overall population was significantly decreased after ERA treatment, NT proBNP level before treatment showed poor correlation with those at 6 months (R2=0.32). However, change of NT proBNP at 1 month from baseline showed strongly correlated with change of NT proBNP at 6 months from baseline with linear regression model analysis (R2 =0.90, p<0.001). Conclusions Assessment of early change in nt-proBNP with only a month of treatment is associated with midterm response to ERA treatment in PAH. It can help to early decision making for early intensive therapy and rapid escalation of PAH medication in non-responsive PAH patients for initial therapy. The relationship of BNP Funding Acknowledgement Type of funding source: Private company. Main funding source(s): Handok