OBJECTIVES. The goals were to assess the frequency of spontaneous closure of isolated secundum atrial septal defect in children and to identify predictors of spontaneous atrial septal defect closure.
METHODS. A retrospective cohort study was performed in a tertiary care pediatric cardiology center. Consecutive patients (n = 200) diagnosed as having isolated atrial septal defects (no multiple or fenestrated atrial septal defects, no additional congenital heart disease, and no syndromes) were monitored for >6 months with serial 2-dimensional echocardiography, according to a standardized protocol.
RESULTS. The median age at diagnosis was 5 months (minimum: 0 months; maximum: 13.9 years). The atrial septal defect diameter at diagnosis was 4 to 5 mm in 40% of cases, 6 to 7 mm in 28% of cases, 8 to 10 mm in 21% of cases, and >10 mm in 11% of cases. The median age at the final follow-up evaluation was 4.5 years (range: 6.8 months to 16.2 years). Thirty-four percent of atrial septal defects showed spontaneous closure, and 28% decreased to a diameter of ≤3 mm. Logistic regression analysis revealed atrial septal defect diameter and age at diagnosis as independent predictors of spontaneous closure or regression to ≤3-mm defect size. Of atrial septal defects with a diameter of 4 to 5 mm at diagnosis, 56% showed spontaneous closure, 30% regressed to a diameter of ≤3 mm, and none required surgical closure. Of atrial septal defects with a diameter of >10 mm at diagnosis, none closed spontaneously, whereas 77% required surgical or device closure. Gender and observation time were not associated with spontaneous atrial septal defect closure or regression to ≤3 mm.
CONCLUSIONS. In the present study population of children with atrial septal defects, 62% showed spontaneous closure (34%) or regression to ≤3 mm (28%). Initial atrial septal defect diameter was the main predictor of spontaneous closure.