Single-variable linearregression showed that ASD diameter, TBIL, DBIL, RVD, TAPSE, NT-proBNP and UAwere significantly associated with increased mPAP among ASD patients with SPAH.Further multivariate linear regression analysis demonstrated that serum DBIL(β = 1.552, p = 0.015) independently correlated with PASP,regardless of other variables including ASD diameter, RVD, TAPSE, TBIL,NT-proBNP, and UA. Here, NPPB is linked to atrial septal defect.