Prognostic Value of Pulmonary Artery Compliance in Patients with Pulmonary Arterial Hypertension Associated with Adult Congenital Heart Disease

In congenital heart disease (CHD), the presence of pulmonary arterial hypertension (PAH) is associated with a poor prognosis. In this study, we aim to investigate the role of pulmonary artery compliance (Cp) in predicting the mortality of PAH associated with adult congenital heart disease (APAH-CHD). One-hundred and seventy-five patients of APAH-CHD who underwent a comprehensive clinical evaluation were included in this study. All patients were followed up in a 6-month interval and the primary end point was all cause of death. The duration of mean follow-up was 67±26 months, of which there were twenty-three death. Cp had an inverse correlation with pulmonary artery resistance (PVR), regardless of the clinical phenotype (Eisenmenger syndrome, PAH with small defect and PAH after defect correction). Patients in the lowest Cp group (Cp ≤ 0.84 mL/mmHg) had advanced WHO function class, worse exercise tolerance, liver function, and status of oxygen saturation. In univariate cox regression analysis, Cp (HR = 1.359, P < 0.001), PVR (HR = 0.972, P = 0.001), pulmonary blood flow (HR = 1.092, P = 0.001), heart rate (HR = 1.038, P = 0.028) and 6-minute walking distance (HR = 1.003, P = 0.037) were predictors of survival. After adjustment by bivariate analysis, Cp was the independent predictor. Kaplan-Meier survival curves showed that patients with Cp < 1.04 mL/mmHg had worse prognosis. In conclusion, Cp possibly reflects disease severity and decreased Cp was associated with poor prognosis in patients with APAH-CHD.