Impact of Transcatheter Occlusion of a Patent Ductus Arteriosus on Atrial Septal Defect Diameter in Children

Background.  A persistent patent ductus arteriosus (PDA) may delay closure of a coexisting atrial septal defect (ASD) due to volume loading and enlargement of the left atrium. The purpose of this study was to investigate the natural history of ASD size in patients with a PDA following transcatheter PDA occlusion. Methods.  All patients with an ASD and a PDA who underwent transcatheter PDA occlusion at Texas Children’s Hospital were identified. Patients with ASD diameter <3 mm, or additional cardiac defects were excluded. Eight patients (7 females) with small- to moderate-sized ASDs and a PDA were identified. Patient demographics, echocardiographic data, and cardiac catheterization data were recorded. Data were analyzed by 1-tailed t-test. Results.  Following PDA occlusion, ASD diameter decreased in 6 of 8 patients by a mean of 3.8 mm (±2.3 mm), including 2 that closed. The median duration of follow-up was 689 days. One ASD remained unchanged and 1 increased in size. The mean maximum ASD diameter decreased from 6.4 mm (±2.2 mm) to 3.9 mm (±3.4 mm) (P = .03). Two patients underwent subsequent transcatheter ASD occlusion. Conclusion.  Following transcatheter PDA occlusion, small- to moderate-sized ASDs have significant probability to decrease in size, and possibly close. In infants and children, we recommend transcatheter PDA occlusion, and serial follow-up of the size of the ASD. This will allow many small- to moderate-sized ASDs to either close, or become smaller, obviating the need for future intervention.