Amplatzer Amulet Left Atrial Appendage Occluder IDE - Amulet IDE

Aug 15, 2023
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Author/Summarized by Author:
Anthony A. Bavry, MD, MPH, FACC
Summary Reviewer:
Deepak L. Bhatt, MD, MPH, MBA, FACC; Kim A. Eagle, MD, MACC
Trial Sponsor:
Abbott
Date Presented:
09/17/2022
Date Published:
08/14/2023
Date Updated:
08/15/2023
Original Posted Date:
08/30/2021
References

Contribution To Literature:

Highlighted text has been updated as of August 15, 2023.

The Amulet IDE trial showed that the Amulet device was safe and effective at LAA occlusion.

Description:

The goal of the trial was to evaluate left atrial appendage (LAA) occlusion with the Amulet device compared with the Watchman device among patients with nonvalvular atrial fibrillation (AF).

Study Design

  • Randomization
  • Parallel

Participants with nonvalvular AF who were not suitable for long-term anticoagulation were randomized to the Amulet device (n = 934) versus the Watchman device (n = 944). In the Amulet group, participants were discharged on either dual antiplatelet therapy or aspirin plus oral anticoagulation (OAC) according to investigator discretion. In the Watchman group, participants were discharged on aspirin and warfarin.

A transesophageal echocardiogram was performed at 45 days, and if no leak was detected, OAC was stopped, and dual antiplatelet therapy commenced until 6 months.

  • Total number of enrollees: 1,878
  • Duration of follow-up: 18 months
  • Mean patient age: 75 years
  • Percentage female: 41%

Inclusion criteria:

  • Nonvalvular AF (paroxysmal, persistent, or permanent)
  • CHA2DS2-VASc score of ≥3
  • Suitable for short-term OAC, but not suitable for long-term OAC

Exclusion criteria:

  • LAA anatomy neither supports a Watchman device nor an Amulet LAA device

Other salient features/characteristics:

  • CHA2DS2-VASc score: 4.5
  • OAC at discharge: 21.1% in the Amulet group vs. 95.8% in the Watchman group
  • Antiplatelet therapy/none at discharge: 78.9% in the Amulet group vs. 4.2% in the Watchman group

Principal Findings:

Primary outcomes:

  • Primary safety endpoint, composite of all-cause mortality, procedure-related complications, or major bleeding at 12 months: 14.5% with Amulet vs. 14.7% with Watchman (p for noninferiority < 0.001)
  • Primary efficacy endpoint, composite of ischemic stroke or systemic embolism at 18 months: 2.8% with Amulet vs. 2.8% with Watchman (p for noninferiority < 0.001)
  • Primary mechanism of action endpoint, residual jet around the device ≤5 mm: 98.8% with Amulet vs. 96.8% with Watchman (p for noninferiority < 0.001, p for superiority 0.003)

Secondary outcomes:

  • Procedure-related complications (device embolization or pericardial effusion): 4.5% with Amulet vs. 2.5% with Watchman (p = 0.02)
  • Composite of cardiovascular mortality, ischemic stroke, or systemic embolism: 5.6% with Amulet vs. 7.7% with Watchman (p for noninferiority < 0.0001)
  • Major bleeding at 18 months: 11.6% with Amulet vs. 12.3% with Watchman
  • Device-related thrombus: 3.3% with Amulet vs. 4.5% with Watchman
  • Moderate to severe peridevice leak at 12 months: 10% with Amulet vs. 22% with Watchman (p < 0.001)

Three-year outcomes (Amulet vs. Watchman):

  • Ischemic stroke or systemic embolism: 5.0% vs. 4.6% (p = 0.69)
  • All stroke, systemic embolism, or cardiovascular death: 11.1% vs. 12.7% (p = 0.31)
  • All-cause mortality: 14.6% vs. 17.9% (p = 0.08)
  • Major bleeding: 16.1% vs. 14.7% (p = 0.46)
  • Ischemic stroke that was preceded by device-related thrombus or peri-device leak: 5 events in the Amulet group vs. 20 events in the Watchman group

Sex differences:

  • Major in-hospital adverse events: 1.9% in men vs. 4.4% in women (p < 0.01)
  • Major bleeding: 1.0% in men vs. 3.7% in women (p < 0.01)
  • Pericardial effusion requiring intervention: 0.5% in men vs. 2.0% in women (p < 0.01)
  • Ischemic stroke or systemic embolism: 2.6% in men vs. 2.6% in women (p = 0.98)
  • Peri-device leak and device-related thrombosis: similar between the groups

Interpretation:

Among patients with nonvalvular AF, the Amulet device was effective at LAA occlusion. The Amulet device was superior to the Watchman device at achieving no/minimal residual leaks around the device at 12 months. The Amulet device was noninferior to the Watchman device with regard to safety at 12 months. The Amulet device was noninferior to the Watchman device with regard to efficacy at 3 years. Efficacy was similar between men and women. There were more procedure-related complications with Amulet (device embolization and pericardial effusion), which decreased with operator experience. Bleeding complications were higher among women. Device-related thrombus was low with the Amulet device despite few participants discharged on anticoagulation (21% in the Amulet group vs. 96% in the Watchman group). Ischemic strokes that were preceded by device-related thrombus or peri-device leak were less frequent in the Amulet group.

References:

Lakkireddy D, Thaler D, Ellis CR, et al. 3-Year Outcomes From the Amplatzer Amulet Left Atrial Appendage Occluder Randomized Controlled Trial (Amulet IDE). JACC Cardiovasc Interv 2023;16:1902-13.

Editorial Comment: Saw J, Offen S. What Have We Learned From the 3-Year Outcomes of the Amulet IDE Trial? JACC Cardiovasc Interv 2023;16:1914-6.

Alkhouli M, Russo AM, Thaler D, et al. Sex Differences in Safety and Effectiveness of Left Atrial Appendage Occlusion: Insights From the Amulet IDE Trial. JACC Cardiovasc Interv 2022;15:2143-55.

Editorial Comment: Nielsen-Kudsk JE. Left Atrial Appendage Occlusion: Sex Matters, but Not in the Long Run. JACC Cardiovasc Interv 2022;15:2156-7.

Presented by Dr. Dhanunjaya Lakkireddy at the Transcatheter Cardiovascular Therapeutics meeting (TCT 2022), Boston, MA, September 17, 2022.

Presented by Dr. Dhanunjaya Lakkireddy at the Transcatheter Cardiovascular Therapeutics (TCT) Conference, Orlando, FL, November 5, 2021.

Lakkireddy D, Thaler D, Ellis CR, et al., on behalf of the Amulet IDE Investigators. Amplatzer™ Amulet™ Left Atrial Appendage Occluder Versus Watchman™ Device for Stroke Prophylaxis (Amulet IDE): A Randomized Controlled Trial. Circulation 2021;144:1543-52.

Presented by Dr. DJ Lakkireddy at the European Society of Cardiology Virtual Congress, August 30, 2021.

Clinical Topics: Anticoagulation Management, Arrhythmias and Clinical EP, Noninvasive Imaging, Prevention, Anticoagulation Management and Atrial Fibrillation, Implantable Devices, SCD/Ventricular Arrhythmias, Atrial Fibrillation/Supraventricular Arrhythmias, Echocardiography/Ultrasound

Keywords: Anticoagulants, Arrhythmias, Cardiac, Aspirin, Atrial Appendage, Atrial Fibrillation, Brain Ischemia, Echocardiography, Transesophageal, Embolism, ESC21, ESC Congress, Hemorrhage, Ischemic Stroke, Patient Discharge, Platelet Aggregation Inhibitors, Secondary Prevention, Stroke, TCT21, TCT22, Thrombosis, Transcatheter Cardiovascular Therapeutics, Warfarin


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