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

## TL;DR

This study examines the clinical outcomes of closing iatrogenic atrial septal defects during mitral valve procedures and finds no significant benefits, with potential risks in patients with severe pulmonary hypertension.

## Contribution

The study provides new insights into the clinical outcomes of iASD closure during TS MViV procedures, particularly highlighting risks in patients with severe pulmonary hypertension.

## Key findings

- No significant differences in procedural success, complications, stroke, or mortality between iASD closure and non-closure groups.
- Patients with severe pulmonary hypertension had higher 30-day mortality and 1-year cardiac readmission rates after iASD closure.
- iASD closure during TS MViV is well-tolerated but offers no significant clinical benefits in most patients.

## Abstract

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.

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.

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%; P = .26), or mortality (18.8% vs 17.3%; P = .54). Rates of New York Heart Association class III/IV and heart failure rehospitalization were also similar. However, in patients with severe pulmonary hypertension (mean pulmonary artery pressure, 47.4 ± 8.6 mm Hg), iASD closure was associated with higher 30-day mortality (9.7% vs 3.9%; P = .03) and 1-year cardiac readmission rates (14.1% vs 4.1%; P = .008).

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.