Do small primum atrial septal defects (ASD) require closure?

From the Guidelines

Small primum atrial septal defects (ASDs) typically do not require closure if they are truly small (less than 5 mm) and hemodynamically insignificant, as indicated by the absence of right ventricular (RV) volume overload 1.

Key Considerations

• The decision to close a small primum ASD should be individualized based on the patient's clinical presentation, the size of the defect, and associated cardiac abnormalities.
• For asymptomatic patients with small primum ASDs without significant shunting (Qp:Qs ratio less than 1.5:1) or chamber enlargement, conservative management with regular cardiac follow-up every 2-5 years is generally recommended 1.
• Echocardiographic monitoring is essential to assess for any changes in defect size, shunt magnitude, or development of pulmonary hypertension.
• Primum ASDs differ from secundum defects as they are located in the lower part of the atrial septum and may be associated with mitral valve abnormalities, making careful evaluation of the mitral valve crucial 1.

Management Approach

• Surgical closure is required for primum ASDs, as they are not amenable to device closure 1.
• The presence of associated cardiac abnormalities, such as mitral regurgitation, may influence the decision toward surgical intervention regardless of defect size.
• Regular follow-up and monitoring are essential to assess for any changes in the patient's condition and to guide management decisions.

Important Considerations

• The patient's clinical presentation, defect size, and associated cardiac abnormalities should be carefully evaluated to guide management decisions.
• Endocarditis prophylaxis is not routinely recommended for isolated ASDs 1.
• The rationale for conservative management is that small primum defects often do not cause significant hemodynamic burden on the heart and may not progress over time.

From the Research

Small Primum Atrial Septal Defects (ASD) Closure

• The need for closure of small primum atrial septal defects (ASD) is a topic of discussion, with various studies providing insights into the benefits and risks of closure 2, 3, 4, 5, 6.
• According to a study published in 2012, transcatheter closure of secundum atrial septal defects in infants less than 12 months of age can improve symptoms of chronic lung disease, suggesting that closure may be beneficial in certain cases 2.
• Another study from 2005 found that early surgical closure of isolated secundum atrial septal defects in infancy can improve clinical performance, growth, and development, and prevent the onset of irreversible changes in the pulmonary vasculature 3.
• A 2014 review of atrial septal defects noted that surgical closure is safe and effective, and when done before age 25 years, is associated with normal life expectancy 4.
• A comparison of percutaneous and surgical closure of secundum atrial septal defects found that percutaneous closure had a lower complication rate and required a shorter hospital stay 5.
• However, a 2022 case report suggested that the closure of small atrial septal defects in patients with pulmonary arterial hypertension should be made on a case-by-case basis, taking into account the benefits and risks specific to each patient 6.

Considerations for Closure

• The decision to close a small primum atrial septal defect should consider factors such as the patient's age, symptoms, and presence of other health conditions 2, 3, 4, 5, 6.
• The type of closure, whether surgical or percutaneous, should also be considered, with percutaneous closure potentially offering a less invasive alternative for eligible patients 5.
• The potential risks and benefits of closure, including the risk of complications and the potential for improved clinical outcomes, should be carefully weighed in each individual case 2, 3, 4, 5, 6.