Is left atrial appendage excision required in patients with atrial septal defect, severe tricuspid regurgitation, and atrial fibrillation?

Left Atrial Appendage Excision in Patients with Atrial Septal Defect, Severe Tricuspid Regurgitation, and Atrial Fibrillation

Left atrial appendage (LAA) excision is strongly recommended for patients with atrial septal defect, severe tricuspid regurgitation, and atrial fibrillation who are undergoing cardiac surgery. This recommendation is supported by multiple guidelines that recognize the benefit of surgical LAA excision in reducing thromboembolic risk in this specific patient population.

Evidence-Based Rationale

Guidelines Supporting LAA Excision

• The 2020 American Heart Association/American College of Cardiology guidelines provide a Class IIb recommendation for LAA excision during cardiac surgery in patients with AF 1.
• More importantly, for patients with AF who are undergoing valve surgery, LAA ligation/excision is considered reasonable (Class IIa, Level B-NR) to reduce the risk of thromboembolic events 1.
• The European Society of Cardiology has issued a Class I, Level B recommendation for LAA occlusion in patients with AF undergoing cardiac surgery 2.

Mechanism of Benefit

• The LAA is the predominant site of thrombus formation in AF patients, accounting for approximately 90% of atrial thrombi in non-valvular AF.

• Patients with the combination of:

  • Atrial septal defect (creating abnormal blood flow patterns)
  • Severe tricuspid regurgitation (causing right atrial enlargement and stasis)
  • Atrial fibrillation (promoting thrombogenesis)

  Have multiple risk factors for thrombus formation and subsequent cardioembolic events.

Clinical Outcomes

• The LAAOS III trial demonstrated a 33% reduction in stroke risk when LAA occlusion was performed during cardiac surgery 2.
• In patients with AF undergoing valve surgery, LAA excision has shown significant benefits in reducing thromboembolic complications.

Procedural Considerations

Timing of LAA Excision

• LAA excision should be performed concurrently with the primary cardiac surgery addressing the atrial septal defect and tricuspid valve.
• This approach avoids the need for a separate procedure and additional anesthesia risk.

Technique

• Complete excision of the LAA is preferred over exclusion techniques when feasible.
• If complete excision is not possible, careful closure with double-layer suturing or dedicated LAA occlusion devices should be considered.
• Intraoperative transesophageal echocardiography should confirm complete LAA closure.

Post-Procedure Anticoagulation

• After LAA excision during cardiac surgery, anticoagulation therapy is reasonable for at least 3 months 1.
• Long-term anticoagulation decisions should be based on the patient's CHA₂DS₂-VASc score and presence of other risk factors.

Special Considerations

Atrial Septal Defect and Tricuspid Regurgitation

• Atrial septal defects can be complicated by cardioembolic strokes through paradoxical embolism 3.
• Tricuspid regurgitation associated with atrial septal defects often improves after ASD closure 4, but the presence of AF significantly increases thromboembolic risk regardless.

Rhythm Control Strategy

• Consider concomitant surgical ablation for AF (maze procedure) along with LAA excision for comprehensive management.
• The combination of rhythm control and LAA excision provides synergistic benefits in reducing stroke risk.

Potential Risks

• Incomplete LAA closure can potentially increase stroke risk due to reduced LAA contractility with persistent communication.
• Procedural complications are rare but include bleeding and injury to surrounding structures.

In conclusion, for patients with the triad of atrial septal defect, severe tricuspid regurgitation, and atrial fibrillation undergoing cardiac surgery, LAA excision should be performed as part of the surgical approach to reduce thromboembolic risk and improve long-term outcomes.