Clinical Outcomes for Closure of Iatrogenic Atrial Septal Defects Following Transseptal SAPIEN Mitral Valve-in-Valve Procedures.

Background: Iatrogenic atrial septal defects (iASD) are created during transseptal (TS) mitral valve-in-valve (MViV) implantation to facilitate access. Although most iASD remain untreated, the outcomes of closing iASD during TS MViV are unclear. This study evaluates outcomes of concomitant iASD closure during TS MViV. Methods: Patients undergoing TS MViV with SAPIEN 3/Ultra/Resilia valves from June 2015 to September 2023 were identified using the Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapy Registry. To reduce patient selection bias in the primary analysis, MViV patients without iASD closure were chosen from sites that did not perform iASD closures. Propensity score matching accounted for baseline characteristics, and analyses evaluated procedural success, complications, and 1-year clinical outcomes. Results: Among 5363 TS MViV patients, 472 (8.8%) underwent iASD closure at 173 of 494 sites (35.0%). Propensity matching yielded 468 patient pairs (34% male, 66% female). No significant differences were observed in procedural success, complications, stroke (3.3% vs 5.2%; Conclusions: Iatrogenic atrial septal defect closure during the index hospitalization for TS MViV patients is a well-tolerated procedure when performed in carefully selected individuals. However, no significant clinical benefits were observed in the iASD closure group. Additionally, patients with significant pulmonary hypertension did not demonstrate any clinical advantage from iASD closure, and the procedure may even pose potential harm in this subgroup.