What is the recommended technique for left atrial (LA) appendage closure in patients at high risk of bleeding or with a history of atrial fibrillation?

Technique of Left Atrial Appendage Closure

For patients with atrial fibrillation at high stroke risk who have contraindications to long-term anticoagulation, percutaneous LAA closure using either the WATCHMAN or Amplatzer Amulet device via transseptal approach is the recommended technique, with both devices demonstrating comparable safety and efficacy. 1, 2

Device Selection and Technical Approach

Available Percutaneous Devices

• The WATCHMAN device (Boston Scientific) and Amplatzer Amulet (St. Jude Medical) are the two primary self-expanding devices placed trans-septally in the LAA and have the most robust clinical evidence 1, 2

• The Amulet IDE trial demonstrated that both devices are noninferior for safety (14.5% vs 14.7% composite events) and effectiveness (2.8% vs 2.8% ischemic stroke/systemic embolism), though Amulet achieved superior LAA occlusion rates (98.9% vs 96.8%) 2

• Procedure-related complications occur in 2.5-4.5% of cases, with pericardial effusion and device embolization being the primary concerns 2, 3

Surgical Techniques

• Surgical LAA excision is recommended as adjunctive therapy during concomitant cardiac surgery (Class I, Level B recommendation) and reduces stroke risk by 33% (HR 0.67) when added to anticoagulation 4, 5

• Excision techniques achieve 73% complete occlusion compared to only 23% for suture exclusion and 0% for stapling alone, making excision the preferred surgical approach 4

• Incomplete surgical occlusion occurs in approximately 50-60% of cases overall and paradoxically increases stroke risk due to thrombus formation in residual LAA stumps 4, 5

Procedural Requirements and Learning Curve

Operator Experience

• A significant learning curve exists for LAA closure, with serious pericardial effusions occurring in 7.1% of the first 3 implant patients at each site compared to 4.4% of subsequent patients 1

• The PREVAIL trial demonstrated that new implanters can achieve success and complication rates comparable to experienced operators when proper training protocols are followed 1

Imaging Requirements

• Transesophageal echocardiography is essential for procedural guidance and has 93-100% sensitivity and 99% specificity for detecting LAA thrombi 5

• TEE at 6 weeks post-procedure is mandatory to assess for device-related thrombus (occurring in 1.7-7.2% of cases), peri-device leak (present in ~25% of cases), and complete LAA occlusion 6, 5

Post-Procedural Anticoagulation Protocol

Standard Regimen

• Oral anticoagulation for 45 days post-procedure, followed by dual antiplatelet therapy (aspirin plus clopidogrel) for 6 months, then aspirin monotherapy indefinitely 6

• Adequate periprocedural anticoagulation with intravenous heparin is essential, with loading doses of 500 mg aspirin or 300-600 mg clopidogrel recommended if not already taking these medications 6

• DAPT or oral anticoagulation at hospital discharge are protective against device-related thrombus formation 6

Critical Clinical Pitfalls

Incomplete Occlusion

• Incomplete LAA occlusion is the most dangerous complication, occurring in approximately 50% of surgical cases and associated with paradoxically increased stroke risk 4, 5

• Peri-device leaks (0-5 mm) occur in approximately 25% of percutaneous cases and require continued monitoring 6, 5

Device-Related Thrombus

• Device-related thrombus formation occurs in 1.7-7.2% of cases and is associated with higher ischemic stroke risk 6, 5

• TEE surveillance at 6 weeks is non-negotiable for detecting this complication 6

Procedural Complications

• Major bleeding and incomplete LAA occlusion are the primary risks of surgical excision 1

• Damage to the circumflex coronary artery is a specific risk due to its proximity to the LAA base 5

• Pericardial effusion requiring drainage occurs in 4.4-7.1% of percutaneous cases, particularly early in the learning curve 1, 2

Patient Selection and Indications

Guideline-Based Recommendations

• Percutaneous LAA closure receives a Class IIb recommendation only for patients with absolute contraindications to long-term oral anticoagulation 1, 4

• Surgical LAA closure during cardiac surgery receives a Class I, Level B recommendation as adjunctive therapy to anticoagulation 4, 5

• LAA closure is not indicated simply as an alternative to oral anticoagulation for stroke risk reduction in patients who can tolerate anticoagulation 1

Important Limitations

• The LAA is the main but not the only site of thrombus formation in AF—approximately 10% of thrombi originate elsewhere in the left atrium 1, 5

• No randomized trials compare LAA occlusion devices with direct oral anticoagulants (NOACs), only with warfarin 4

• Most patients still require some form of antithrombotic therapy post-procedure, which carries bleeding risks that may be equivalent to NOACs 5