What are the current recommendations for Atrial Septal Defect (ASD) closure eligible by device criteria?

Current Recommendations for ASD Closure Eligible by Device Criteria

For adults with secundum ASD meeting device criteria, transcatheter closure is recommended when there is right atrial and/or RV enlargement with Qp:Qs ≥1.5:1, provided PA systolic pressure is <50% of systemic pressure and PVR is <1/3 systemic vascular resistance, regardless of symptom status. 1

Primary Indications for Device Closure

Symptomatic Patients (Class I Recommendation)

• Device closure is recommended for adults with isolated secundum ASD causing impaired functional capacity, right atrial and/or RV enlargement, and Qp:Qs ≥1.5:1 without cyanosis, when PA systolic pressure <50% systemic and PVR <1/3 systemic resistance. 1
• The goal is to reduce RV volume overload and improve exercise tolerance. 1

Asymptomatic Patients (Class IIa Recommendation)

• Device closure is reasonable in asymptomatic adults when right atrial and RV enlargement are present with Qp:Qs ≥1.5:1, meeting the same hemodynamic criteria (PA pressure <50% systemic, PVR <1/3 systemic). 1
• This prevents progression to symptomatic heart failure and atrial arrhythmias. 2

Critical Hemodynamic Thresholds

Favorable Hemodynamics (Proceed with Closure)

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

Borderline Hemodynamics (Consider Closure with Caution - Class IIb)

• PA systolic pressure 50-67% of systemic pressure 1
• PVR 1/3 to 2/3 systemic resistance (5-10 Wood units) 1
• Requires evaluation by pulmonary hypertension specialists and may benefit from vasodilator testing or trial occlusion. 1
• Recent evidence suggests patients with anatomically large defects (>25mm) and reversible PVR may benefit from fenestrated device closure with pulmonary vasodilators. 3

Absolute Contraindications (Class III - Do Not Close)

• PA systolic pressure >2/3 systemic pressure 1
• PVR >2/3 systemic vascular resistance 1
• Net right-to-left shunt (Eisenmenger physiology) 1
• Closure in these patients causes acute RV failure and death. 4

Device-Specific Anatomic Criteria

Favorable Anatomy for Device Closure

• Secundum ASD with stretched diameter <38mm 1, 5
• Adequate rim of ≥5mm in most locations (except toward the aorta where smaller rim acceptable) 1, 6
• Device closure is the preferred method when anatomically suitable, occurring in approximately 80% of secundum ASDs. 1

Deficient Rim Considerations

• Deficiency in one rim (particularly superior anterior) does not significantly influence success rate, though repositioning may be required more frequently. 6
• Large defects (>25mm) with deficient rims may still be amenable to device closure in experienced centers. 5

Special Clinical Scenarios

Paradoxical Embolism

• Device closure should be considered for ASDs of any size when paradoxical embolism is suspected after excluding other causes. 1

Concomitant Cardiac Surgery

• Surgical closure is reasonable when another cardiac procedure is being performed and Qp:Qs ≥1.5:1 with RV enlargement, even if ASD was not the primary indication. 1

Small Defects (<5mm)

• Do not require closure unless associated with paradoxical embolism, as they do not impact natural history. 2

Defects NOT Eligible for Device Closure

The following require surgical repair rather than device closure: 1

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

Critical Pitfalls to Avoid

Underestimating Risk in Older Adults

• Acquired conditions (hypertension, coronary disease, valvular disease) increase left-to-right shunting over time, making previously insignificant ASDs hemodynamically relevant. 4
• Even asymptomatic patients benefit from closure at any age regarding morbidity (exercise capacity, heart failure). 1

Timing of Intervention

• Outcome is best with repair before age 25 years; surgery after this age results in reduced survival compared to age-matched controls. 2
• Nearly 25% of patients with unoperated ASDs die before age 27, and 90% by age 60. 2

Pulmonary Hypertension Assessment

• The most critical assessment is excluding severe PAH before closure. 4
• Invasive hemodynamic assessment is required when PA pressure is elevated on echocardiography. 1

Post-Procedure Monitoring

• Antiplatelet therapy (aspirin 100mg daily minimum) is required for at least 6 months. 1, 7
• Device erosion, though rare (<1%), is life-threatening and requires urgent evaluation if new chest pain or syncope develops. 7
• Pericardial effusion may develop up to several weeks post-procedure. 7
• Atrial arrhythmias occur in 15-25% of adult patients, particularly those closed after age 40. 7

Expected Outcomes

Device Closure Success Rates

• Procedural success rate is 97-100% in appropriately selected patients. 8, 9, 6
• Complete closure rate is 82% immediately, increasing to 97% at 6-24 months follow-up. 9, 6
• Serious complications occur in ≤1% of patients. 1, 2
• Early mortality is approximately 1% in the absence of PAH or major comorbidities. 1, 2

Clinical Improvement

• 89% of patients show improvement in symptoms at 6 months. 9
• RV end-diastolic dimension decreases significantly (from 38.9±9mm to 26.6±7mm). 9
• Right heart remodeling occurs even in patients >60 years of age. 9