close up of WATCHMAN FLX device on white background


The first head-to-head comparison of occlusion properties of the WATCHMAN FLX device and the Amplatzer Amulet device using cardiac computed tomography (CT).

Study design

  • Single-center, retrospective study of LAAO implantation at Aarhus 
 University Hospital (Denmark) between 2017-2020.
    1st cohort: Amplatzer Amulet (n=150) 2017 – 2019
    2nd cohort: WATCHMAN FLX (n=150) 2019 – 2020
  • Cardiac CT was performed 8 weeks after LAAO
Primary Outcome Complete Seal* Based on CT Imaging

WATCHMAN FLX demonstrated statistically superior complete occlusion* vs Amulet (p<0.001)

Complete occlusion*

Complete LAA Occlusion graph

Complete occlusion* on CT imaging1

The superior complete occlusion* of the WATCHMAN FLX Device was consistent across all anatomies analyzed

Peri-device leak

Peri Device Leak graph

Leak measurements were significantly larger with Amulet than WATCHMAN FLX (p=0.019)

Leak size (mm2)

Peri Device Leak graph

WATCHMAN FLX’s one-component design translates to clear sealing advantages

Simplified sizing


WATCHMAN FLX sizing icon

Single landing zone and overlapping treatment ranges

Amplatzer Amulet2

Amplatzer Amulet sizing icon

Complicated, mis-matched measurements

Simplified placement


WATCHMAN FLX placement icon

Precision placement control

Amplatzer Amulet3

Amplatzer Amulet placement icon

Trade-off between disc and lobe placement

Simplified assessment


WATCHMAN FLX assessment icon

Full visibility

Amplatzer Amulet1

Amplatzer Amulet assessment icon

Hidden leaks

WATCHMAN FLX device with decorative teal overlay

1. Korsholm-K et al. Left atrial appendage sealing performance of the Amplatzer Amulet and Watchman FLX device. J Interv Card Electrophysiol. 2022 Aug 11. doi: 10.1007/s10840-022-01336-4.
2. Lakkireddy, Amulet Tips and Tricks in Simple and Complex Anatomy, TVT 2018.
3. Saw, Cardiac CT angiography for device surveillance after endovascular left atrial appendage closure, European Heart Journal - Cardiovascular Imaging, Volume 16, Issue 11, November 2015, Pages 1198–1206,
* Complete LAA occlusion defined as no visible peri-device leak (PDL) and absence of contrast patency in the distal LAA (LAA/left atrium Hounsfield ratio <0.25)