Small Secundum Atrial Septal Defects Are Associated With Paradoxical Embolism: A Retrospective Study Using...

Area of Science:

• Cardiology
• Medical Imaging
• Interventional Cardiology

Background:

• Paradoxical embolism is a significant complication of secundum atrial septal defect (ASD).
• Predictive anatomical factors for embolic events in ASD patients are not fully understood.
• This study focuses on identifying morphological characteristics, particularly ASD size, associated with paradoxical embolism.

Purpose of the Study:

• To investigate clinical and morphological factors linked to paradoxical embolism in adults undergoing transcatheter ASD closure.
• To determine the specific role of ASD size in the occurrence of paradoxical embolism.

Main Methods:

• Retrospective analysis of 270 adult patients undergoing transcatheter closure of secundum ASD (2013-2024).
• Patients were categorized based on a history of paradoxical embolism.
• ASD morphology, including maximum diameter, was evaluated using intra-operative transesophageal echocardiography (TEE).
• Logistic regression models were used to assess the association between ASD size and paradoxical embolism.

Main Results:

• Paradoxical embolism was observed in 14 out of 270 patients.
• Patients with paradoxical embolism exhibited a significantly smaller maximum ASD diameter (12.92 ± 5.79 mm) compared to those without (16.94 ± 5.96 mm; p=0.02).
• A smaller ASD size (<10 mm) was independently associated with paradoxical embolism (OR 7.75; p<0.001) after multivariable adjustment.

Conclusions:

• Smaller maximum ASD diameter, especially below 10 mm, is consistently associated with paradoxical embolism.
• Even small ASDs (<10 mm) can present a clinically relevant embolic risk in patients undergoing transcatheter closure.
• These findings highlight the importance of considering embolic risk even in cases of seemingly small ASDs.