Preoperative threshold for normalizing right ventricular volume after transcatheter closure of adult atrial septal defect

Background: The latest guidelines recommend early intervention in adult atrial septal defect (ASD) patients with signs of right ventricular (RV) enlargement. However, the criteria of RV enlargement for optimal intervention remain unclear. We investigated the preoperative determinants for normalizing the RV volume after transcatheter closure of ASD in adults. Methods and Results: We retrospectively analyzed 52 ASD patients who underwent transcatheter closure. Cardiac magnetic resonance imaging (CMR) measured RV volume before and 1 year after the closure. The patients were divided into normalized (postoperative RV end-systolic volume index [RVESVI] <47 mL/m² and end-diastolic volume index [RVEDVI] <108 mL/m²) and non-normalized (postoperative RVESVI ≥47 mL/m² or RVEDVI ≥108 mL/m²) groups. Preoperative RVESVI was significantly smaller (72 mL/m² vs. 80 mL/m²) and RVEF was higher (56% vs. 51%) in the normalized group compared with the non-normalized group. Receiver-operating characteristic analysis for the normalization of postoperative RV volume showed that the preoperative threshold value of RVESVI was 75 mL/m². In addition, multivariate analysis showed that preoperative RVESVI was an independent predictor for normalization of RV volume. Conclusions: Preoperative RVESVI is an independent predictor for normalization of RV volume at 1 year after transcatheter closure of ASD in adults. Early intervention before RVESVI reaches 75 mL/m² may confer optimal timing for normalizing RV volume.