Background: Transcatheter closure is an important treatment for patent ductus arteriosus (PDA) complicated with moderate and severe pulmonary arterial hypertension (PAH). This report presents our experience with transcatheter closure of PDA complicated with moderate and severe PAH.Methods: The 49 cases of PDA complicated with moderate and severe PAH were collected in the Second Affiliated Hospital and Yuying Children's Hospital from January 2014 to December 2019 with transcatheter closure of PDA and follow-up. All patients were invited for transthoracic echocardiography, electrocardiogram, and thoracic radiography check-up.Results: Device implantation was successful in 48 of 49 patients (98.0%). Among them, 30 cases were in the PAH after defect correction (CD) group, and 19 examples were in the Non-PAH after defect correction (NCD) group. Pulmonary systolic pressure, left atrial diameter, and left ventricular end-diastolic diameter immediately after interventional therapy and 6 months later were lower than the pre-operative levels (p < 0.05). The incidence of the immediate residual shunt (RS) in this study was 34.9%, most of which were minimal amount shunt. RS disappeared in all patients within 1 year of therapy. Four patients had thrombocytopenia and one patient had left pulmonary artery stenosis. No other serious adverse event occurred during the follow-up period. The pressure gradient tricuspid valve regurgitation (PGTI) and the right heart catheterization (RHC) consistency points were 93.75% (15/16) and were within the 95% consistency limit by the Bland-Altman method. The Logistic regression analysis concluded that the pre-operative Pp/Ps and the narrowest diameter of PDA are risk factors for post-operative PAH (p < 0.05). The cut-off point of the pre-operative Pp/Ps and the narrowest diameter of PDA were calculated to be 0.595 and 4.75 mm, respectively.Conclusion: Interventional occlusion in children with PDA complicated with moderate and severe PAH is safe, effective, and has few complications. Targeted drug therapy has a good clinical effect. The narrowest diameter of PDA and the pre-operative Pp/Ps may be one of the risk factors of residual PAH after interventional therapy.
