Can cardioversion for atrial fibrillation (AF) be performed without anticoagulation in patients with an appendage occluder device?

Cardioversion in Patients with Left Atrial Appendage Occluder Devices

Cardioversion can be performed without anticoagulation in patients with a left atrial appendage occluder device, provided that pre-procedural transesophageal echocardiography (TEE) confirms proper device positioning, absence of device-related thrombus, and peridevice leak ≤5 mm. 1

Pre-Cardioversion Requirements

Mandatory TEE Assessment

• All patients with LAAO devices must undergo TEE before cardioversion to exclude cardiac thrombi and verify adequate device positioning 2, 1
• TEE should specifically assess for:
  • Device-related thrombus (occurs in 1.7-7.2% of cases) 3
  • Proper device position without rotation or embolization 2
  • Peridevice leak ≤5 mm 1

Management of Device-Related Thrombus

• If device-related thrombus is detected (2.7% incidence), treat with oral anticoagulation for 6-8 weeks before proceeding with cardioversion 1
• Repeat TEE after anticoagulation course to confirm thrombus resolution before cardioversion 1

Anticoagulation Strategy Around Cardioversion

Standard Guidelines Do Not Apply

• Current ESC guidelines recommend anticoagulation for at least 3 weeks before and 4 weeks after cardioversion for AF >48 hours duration 4
• However, these recommendations were developed for the general AF population without LAAO devices 2
• The primary rationale for LAAO placement is often contraindication to long-term anticoagulation, making standard protocols impractical 3

Evidence-Based Approach Without Anticoagulation

• A multicenter study of 148 patients with LAAO devices undergoing cardioversion showed zero thromboembolic complications without mandatory anticoagulation when pre-procedural TEE was normal 1
• A prospective registry of 284 cardioversions in 93 patients post-LAAO demonstrated no thromboembolic events during 30-day follow-up, regardless of anticoagulation strategy used 2
• No difference in cardioversion-related complications was observed between patients treated with or without anticoagulation post-cardioversion 1

Timing Considerations

Early Post-Implantation Period

• Patients receiving anticoagulation post-cardioversion underwent the procedure earlier after device implantation (median 3.6 months vs. 8.6 months) 1
• At least one imaging confirmation of adequate device positioning should occur before any cardioversion 2
• Standard post-LAAO protocols recommend TEE at 6 weeks to assess device positioning and exclude thrombus 3

AF Duration

• For AF >24 hours or unknown duration, TEE is mandatory before cardioversion in LAAO patients, even without anticoagulation 4, 1
• For hemodynamically unstable patients requiring immediate cardioversion, proceed emergently after TEE confirmation of proper device position and absence of thrombus 4

Post-Cardioversion Management

Anticoagulation Decision

• Post-cardioversion anticoagulation is not mandatory if pre-procedural TEE shows proper device position, no device-related thrombus, and peridevice leak ≤5 mm 1
• Only 22% of patients in the largest study were newly started on anticoagulation after cardioversion, based on individual risk assessment 1
• Continuation of oral anticoagulation after cardioversion should be based on the original indication for LAAO placement and individual bleeding/thrombotic risk 4

Critical Safety Considerations

Device Complications to Monitor

• Device rotation or embolization can occur and may be detected during pre-cardioversion TEE 2
• During median follow-up of 12.8 months post-cardioversion, no device dislodgement, new device leak, or left atrial thrombosis was observed 1
• Three transient ischemic attacks occurred during follow-up but were unrelated to the cardioversion procedure 1

High Bleeding Risk Patients

• Patients with LAAO devices typically have high bleeding risk (HAS-BLED scores 3.3-3.6), which was the original indication for device placement 5
• In high bleeding-risk patients, minimal or no antithrombotic therapy post-cardioversion may be safer than standard anticoagulation protocols 5
• Standard anticoagulation post-cardioversion resulted in more bleeding events (15% vs. 0%) and associated deaths (9% vs. 0%) in high bleeding-risk patients 5

Practical Algorithm

1. Confirm LAAO device implantation >6 weeks prior (allows standard post-implant healing period) 3
2. Perform mandatory pre-cardioversion TEE to assess:
   • Device position and stability 2, 1
   • Absence of device-related thrombus 1
   • Peridevice leak ≤5 mm 1
3. If TEE shows device-related thrombus: Treat with oral anticoagulation for 6-8 weeks, repeat TEE, then proceed if resolved 1
4. If TEE is normal: Proceed with cardioversion without mandatory anticoagulation 1
5. Post-cardioversion: No routine anticoagulation required; base decision on individual bleeding/thrombotic risk assessment 1, 5

Important Caveat

The ESC guidelines emphasize that continuation of oral anticoagulation is recommended in patients with AF at elevated thromboembolic risk after LAA exclusion, independent of rhythm outcome 4. This creates a nuanced situation where the decision to withhold anticoagulation around cardioversion must weigh the acute procedural risk against the patient's baseline stroke risk (CHA₂DS₂-VASc score) and the original contraindication to anticoagulation that led to LAAO placement 6.