Persistent iatrogenic atrial septal defect after single-puncture, double transseptal access for 4D ICE-guided left atrial appendage occlusion: Incidence and clinical outcomes.

BACKGROUND: Persistent iatrogenic atrial septal defect (iASD) is a known consequence of transseptal puncture (TSP). Large-bore double transseptal access through a single TSP is commonly used for intracardiac echocardiography (ICE)-guided left atrial appendage occlusion (LAAO). This study evaluated the incidence and clinical outcomes of persistent iASD following this approach. METHODS: We retrospectively reviewed LAAO procedures at a single academic center from January 2020 to December 2024. Cases were grouped as: (1) 4D ICE with double transseptal access (n = 58), (2) 2D ICE with double transseptal access (n = 64), or (3) no left atrial (LA) ICE (n = 81). Patients were included if they had follow-up imaging (TEE or cardiac CT). Multivariable logistic regression identified predictors of persistent iASD. RESULTS: Among 203 patients (age 77.1 ± 6.6 years; 59% male), follow-up occurred at 58.0 ± 25.2 days. Persistent iASD was detected in 88 patients (43%). ICE-guided cases had a higher incidence of iASD compared with no LA ICE (54.1% vs. 27.2%; p < 0.001), with no difference between 2D and 4D ICE (p = 0.340). On multivariable analysis, both 2D and 4D ICE were independently associated with increased odds of persistent iASD (2D ICE: OR 3.45, 95% CI 1.46-8.17; 4D ICE: OR 3.57, 95% CI 1.52-8.38). Coronary artery disease was associated with increased odds (OR 2.44, 95% CI 1.12-5.28), while hypertension was associated with decreased odds (OR 0.41, 95% CI 0.18-0.96). Persistent iASD was not associated with adverse clinical outcomes. CONCLUSIONS: Persistent iASD is common following LAAO, occurring in 43% of patients at early follow-up. Left atrial ICE use is independently associated with increased odds of persistent iASD, with similar rates between 2D and 4D ICE techniques.