Profile of Endothelin-1, Nitric Oxide, and Prostacyclin Levels in Pulmonary Arterial Hypertension Related to Uncorrected Atrial Septal Defect: Results from a Single Center Study in Indonesia

Background and Objectives. Pulmonary arterial hypertension (PAH) pathomechanism involves an increased plasma level of endothelin-1 and a reduced plasma level of prostacyclin and nitric oxide. Whether similar mechanisms prevail in PAH associated with atrial septal defect (ASD) is unclear. This study aimed to investigate the relationship of endothelin-1, prostacyclin, and nitric oxide with PAH in uncorrected ASD in Indonesian population. Methods. The study design was cross-sectional. The subjects were adult uncorrected secundum ASD with PAH. Pulmonary artery pressure was measured with right heart catheterization. Pulmonary venous blood was obtained during catheterization for measuring endothelin-1, prostacyclin, and nitric oxide. Correlation tests were performed to determine any association between biomarkers and mean pulmonary artery pressure (mPAP). The levels of biomarkers were compared based on the severity of PAH. Statistical significance was determined at p<0.05. Results. Forty-four subjects were enrolled in this study. Endothelin-1 level and mPAP had significant moderate positive correlation (r = 0.423 and p value = 0.004). However, no significant correlation was observed between prostacyclin, nitric oxide levels, and mPAP. The pattern of endothelin-1, prostacyclin, and nitric oxide was distinctive. Levels of endothelin-1 were incrementally increased from mild, moderate, to severe PAH. The levels of prostacyclin and nitric oxide had similar pattern in association with the severity of PAH, which was increased in mild-to-moderate PAH but decreased in severe PAH. Conclusions. There was a distinctive pattern of endothelin-1, prostacyclin, and nitric oxide based on severity of PAH in adult uncorrected ASD. Significant correlations existed between endothelin-1 and the severity of PAH and mPAP.