Abstract 4146853: Factors Associated with Recovery of Right Ventricular Size After Transcatheter Device Closure of Isolated Atrial Septal Defects in Children

Introduction: Children with significant left-to-right shunting across an isolated atrial septal defect (ASD) may have important right ventricular (RV) dilation. We sought to determine factors associated with RV recovery after percutaneous device closure. Methods: Children who underwent transcatheter device closure of an isolated ASD were included if they had no underlying genetic defect and echocardiography from prior to, immediately after and at follow-up. General linear regression modeling was used to determine factors associated with time-related RV dimensional recovery. Results: Inclusion criteria were met for 385 children (62% females; mean age 8.9 + 4.3 years) whose procedure occurred from 11/1985 to 11/2012. A single defect was present for 85%, with a mean size indexed to BSA of 14.9 + 6.6 mm/m 2 . A single device (Amplatzer for 80%) was used for 97% of the children, with a mild residual shunt present in 14% at the procedure. Mean BSA-indexed RV end-diastolic dimension (RVEDD) immediately post-closure was 2.20 + 0.66 cm/m 2 and decreased at a median follow-up of 1.8 years (range up to 13 years) to 1.71 + 0.48 cm/m 2 (p<0.001), corresponding to a mean BSA-adjusted Z score of +1.51 at follow-up (>+2 for 47% of children). Significant factors associated with a greater reduction in BSA-indexed RV size ( Figure ) included younger age at closure (p<0.001), larger indexed ASD size (p<0.001), greater RV size at closure (p<0.001) and longer follow-up time (p<0.001). Reduction was not associated with the presence of any residual shunt post-closure. QRS duration on ECG did not change significantly from pre-closure (mean 90 + 12 mmsec) to latest ECG (mean 89 + 12; p=035). Conclusions: Despite progressive reductions in RV size after ASD device closure, some children may continue to have RV enlargement. Earlier closure is associated with greater improvements.