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Updated: Jan 10, 2026
The WATCHMAN Left Atrial Appendage Closure Device for Atrial Fibrillation
Published on: February 28, 2012
Comparing Effectiveness and Safety of Left Atrial Appendage Closure Devices: A Network Meta-Analysis of Randomized
John W Davis1, Steven L Mai2, Wissam Harmouch2
1Department of Internal Medicine, Washington University in St. Louis/Barnes-Jewish Hospital, St. Louis, Missouri, USA.
Insights
The Amplatzer Amulet and Watchman left atrial appendage closure (LAAC) devices show similar risks for stroke, death, and device embolization. However, Amulet has a higher risk of pericardial effusion compared to Watchman.
Area of Science:
- Cardiology
- Medical Devices
- Interventional Cardiology
Background:
- Atrial fibrillation-related stroke is a significant cause of death and disability.
- The comparative effectiveness and safety of different left atrial appendage closure (LAAC) devices, and their comparison to anticoagulation, require further clarification.
Purpose of the Study:
- To conduct a systematic review and network meta-analysis (NMA) comparing the Watchman and Amplatzer Amulet LAAC devices.
- To compare LAAC devices against each other and against warfarin or direct oral anticoagulants (DOACs).
- To evaluate primary effectiveness outcomes (stroke, all-cause death) and safety outcomes (thromboembolism, device embolization, pericardial effusion).
Main Methods:
- Systematic review and network meta-analysis (NMA) of randomized controlled trials (RCTs).
- Included 6 RCTs with 3666 participants comparing Watchman and Amulet LAAC devices, warfarin, or DOACs.
- Primary comparisons focused on LAAC devices, with secondary comparisons to anticoagulation.
Main Results:
- No significant difference in stroke risk between Amulet and Watchman (RR=1.48, 95% CI: 0.64-3.46).
- No significant difference in all-cause death risk between Amulet and Watchman (RR=1.00, 95% CI: 0.59-1.70).
- Higher risk of pericardial effusion with Amulet compared to Watchman (RR=2.12, 95% CI: 1.45-3.09).
Conclusions:
- The Amplatzer Amulet and Watchman LAAC devices demonstrate comparable risks for stroke, mortality, thromboembolism, and device embolization.
- The risk of pericardial effusion is significantly higher with the Amulet device than with the Watchman device.
- Both LAAC devices showed an increased risk of pericardial effusion compared to warfarin.
Introduction:
Atrial fibrillation-related stroke is a leading cause of morbidity and mortality. The comparative effectiveness and safety of left atrial appendage closure (LAAC) devices, compared with one another and with anticoagulation, is unclear.
Methods:
We conducted a systematic review and network meta-analysis (NMA) of all clinical trials comparing the Watchman and Amplatzer Amulet LAAC devices with each other or with warfarin or direct oral anticoagulants (DOACs). The primary comparison was between LAAC devices with secondary comparisons to anticoagulation. The primary effectiveness outcomes were any stroke and all-cause death. Safety outcomes included any thromboembolism, device embolization, and pericardial effusion.
Results:
There were 476 articles identified from the search and 6 eligible RCTs were included (n = 3666). There was no difference in the risk of stroke with Amulet versus Watchman (RR = 1.48, 95% CI: 0.64-3.46, I2 = 41.3%), nor in the risk of death (RR = 1.00, 95% CI: 0.59-1.70, I2 = 45.0%). Risk of thromboembolism was not significantly different with Amulet versus Watchman (RR = 0.73, 95% CI: 0.18-2.97, I2 = 0%), nor was risk of device embolization (RR = 2.29, 95% CI: 0.71, 7.43, I2 = 0%). Both devices exhibited increased risk of pericardial effusion compared with warfarin, with Amulet at highest relative risk (RR = 27.08, 95% CI: 3.53-207.98, I2 = 0%) followed by Watchman (RR = 12.79, 95% CI: 1.73-94.85, I2 = 0%). Amulet also carried higher relative risk of pericardial effusion than Watchman (RR = 2.12, 95% CI: 1.45-3.09).
Conclusion:
In this NMA, the Amulet and Watchman LAAC devices were associated with similar risks for stroke, mortality, thromboembolism, and device embolization. Pericardial effusion risk was higher with Amulet than Watchman.
