What are the management options for a patient with Atrial Septal Defect (ASD)?

Management of Atrial Septal Defect (ASD)

Percutaneous device closure is the first-line treatment for secundum ASDs with right ventricular enlargement, while surgical closure is mandatory for all other ASD subtypes (sinus venosus, primum, and coronary sinus defects). 1, 2

Indications for ASD Closure

Closure is indicated for any ASD causing right atrial and right ventricular enlargement, regardless of symptoms. 1, 2 This recommendation prioritizes prevention of long-term mortality and morbidity, as unoperated ASDs result in 25% mortality before age 27 and 90% mortality by age 60. 2

Specific Hemodynamic Criteria for Closure:

• Qp:Qs ratio ≥1.5:1 with evidence of RV volume overload 1, 2
• Pulmonary artery systolic pressure <50% of systemic pressure 1
• Pulmonary vascular resistance <1/3 systemic resistance (<5 Wood units) 1

Small Defects (<5 mm):

• Do not require closure unless associated with paradoxical embolism 3, 2
• No evidence of RV volume overload means the defect does not impact natural history 3

Treatment Algorithm by ASD Subtype

Secundum ASD:

Percutaneous device closure is preferred when anatomically suitable 1, 2, 4:

• Stretched diameter <38 mm 2
• Adequate rim ≥5 mm in most locations (smaller rim acceptable toward aorta) 2
• Device options include Amplatzer Septal Occluder (most common), Gore HELEX (small-medium defects), and Amplatzer Cribriform device (fenestrated ASDs) 4
• Treatment efficacy 97.3% with serious complications ≤1% 2

Surgical closure is indicated when:

• Device closure is not anatomically feasible 3, 1
• Concomitant tricuspid valve repair/replacement is needed 1
• Another cardiac procedure is being performed with Qp:Qs ≥1.5:1 and RV enlargement 2

Non-Secundum ASDs:

Surgical closure is mandatory for all of the following 3, 1, 2:

• Sinus venosus defects
• Primum defects
• Coronary sinus defects
• ASDs with anomalous pulmonary venous drainage

Surgical approach includes:

• Pericardial or synthetic patch closure via sternotomy or right thoracotomy 3
• Warden procedure (SVC translocation to right atrial appendage) for sinus venosus ASD with anomalous pulmonary venous drainage entering mid/upper SVC 3
• Tricuspid valve repair for significant regurgitation 3
• Early mortality approximately 1% without PAH or major comorbidities 3, 2

Absolute Contraindications to Closure

Do not close ASDs in the following scenarios 3, 1:

• Severe irreversible PAH with no evidence of left-to-right shunt (Eisenmenger physiology) 3, 1
• PA systolic pressure >2/3 systemic pressure 1
• PVR >2/3 systemic resistance 1
• Net right-to-left shunt 1

Critical pitfall: Closure with established severe pulmonary vascular disease is fatal. 1 Always exclude severe PAH before proceeding with closure. 1

Management of Associated Conditions

Atrial Arrhythmias:

• Treat to restore and maintain sinus rhythm with anticoagulation for atrial fibrillation 1
• Pre-closure ablation is reasonable for patients with supraventricular tachycardia 1
• Concomitant Maze procedure may be considered during surgical closure for intermittent or chronic atrial tachyarrhythmias 3

Pulmonary Hypertension:

• Patients with PAH require evaluation by providers with expertise in pulmonary hypertensive syndromes before considering closure 3, 2

Post-Closure Monitoring

Immediate Post-Procedure:

Monitor for postpericardiotomy syndrome symptoms 3, 2:

• Undue fever, fatigue, vomiting, chest pain, or abdominal pain
• Perform immediate echocardiography if these symptoms develop to assess for tamponade 3, 2

Long-Term Follow-Up:

Annual clinical follow-up is required if ASD was repaired as an adult and the following persist or develop 3:

• Pulmonary arterial hypertension
• Atrial arrhythmias
• RV or LV dysfunction

Expected Outcomes

Closure improves mortality, functional status, and cardiac parameters 2:

• Improvement in NYHA functional class 2
• Reduction in RV systolic pressure, volumes, and dimensions 2
• Weak protective effect on adjusted mortality rate 2
• Best outcomes achieved with repair before age 25 years 2

Critical Clinical Pitfalls to Avoid

Do not assume small shunts are benign in older adults 1: Acquired conditions (hypertension, coronary disease, diastolic dysfunction) can increase left-to-right shunting over time, making previously insignificant ASDs hemodynamically relevant. 1

Do not delay closure based on absence of symptoms 2: Symptoms lag behind objective cardiopulmonary dysfunction and cannot guide therapy. Surgery after age 25 results in reduced survival compared to age-matched controls. 2

Meticulous air bubble elimination from all IV lines is mandatory 5: Even predominantly left-to-right shunts carry paradoxical embolism risk. 5