Comparison of Amplatzer Amulet and Watchman Device in Patients Undergoing Left Atrial Appendage Closure. (SWISS-APERO)

  • End date
    Dec 26, 2025
  • participants needed
  • sponsor
    University Hospital Inselspital, Berne
Updated on 26 January 2021


Left atrial appendage closure (LAAC) is an emerging therapeutic option in non-valvular atrial fibrillation (NVAF) patients with high thromboembolic and bleeding risks. In Europe the devices most frequently utilized for LAAC are Amplatzer Amulet (St. Jude Medical-Abbott) and Watchman (Boston Scientific) system. However there are currently no randomized controlled trials assessing the degree of LAA closure between the two devices. The main purpose of this trial is to evaluate the feasibility and the efficacy of the devices in terms of LAA complete occlusion with a non-invasive imaging technique such as cardiac computed tomography angiography (CCTA).


Non-valvular Atrial fibrillation (NVAF) is the most common cardiac arrhythmia and a major cause of morbidity and mortality because of cardioembolic stroke. Oral anticoagulation (OAC) with vitamin K antagonists (VKA) or Non-vitamin K antagonist anticoagulant (NOAC) is the most effective prophylaxis for stroke in NVAF. However (N)OAC therapy is associated with a significant bleeding liability and long-term (N)OAC therapy in patients with NVAF and concomitant high bleeding risk poses safety issues in a sizable and growing population in clinical practice. Thus, a new and emerging therapeutic option in this high-risk patient population is the left atrial appendage closure (LAAC). There are many available systems approved for percutaneous LAAC. One of the most widely used is the Watchman system (Boston Scientific), which was tested in the setting of two randomized control trials (RCT), which demonstrated the safety of the procedure and the non-inferiority in terms of stroke reduction compared to OAC. Another device largely used is the Amplatzer Amulet (St. Jude Medical-Abbott). There is no RCT comparing this device with OAC, but many prospective and retrospective studies had shown the same safety profile and the non-inferiority with the OAC. From the very beginning of the LAAC, a crucial assessment is the degree of LAA occlusion granted by the implanted device. Many imaging modalities have been used to assess LAA occlusion, including transesophageal echocardiography (TEE), fluoroscopy or cardiac computed tomography angiography (CCTA). In the setting of available randomized trials, successful closure was defined with the presence of a regurgitant flow 5 mm assessed with TEE. In the last years several groups assessed the value of CCTA as non-invasive post-procedural surveillance imaging modality after endovascular LAAC to evaluate atrial-side device thrombus, residual leak (and mechanisms thereof), device position, pericardial effusion and most importantly LAA patency. There are currently no randomized controlled trials assessing the degree of LAA occlusion between Amulet and Watchman.

Condition Left Atrial Appendage Closure
Treatment Amplatzer Amulet for left atrial appendage closure, Watchman for left atrial appendage closure, Watchman/FLX for left atrial appendage closure
Clinical Study IdentifierNCT03399851
SponsorUniversity Hospital Inselspital, Berne
Last Modified on26 January 2021


Yes No Not Sure

Inclusion Criteria

Is your age greater than or equal to 18 yrs?
Gender: Male or Female
Do you have Left Atrial Appendage Closure?
Do you have any of these conditions: Do you have Left Atrial Appendage Closure??
Do you have any of these conditions: Do you have Left Atrial Appendage Closure??
Do you have any of these conditions: Do you have Left Atrial Appendage Closure??
Written informed consent
Male or female subject aged 18 years or more with no upper age limit and willing to comply with the protocol
Indication to a LAAC as indicated in study population (HAS BLEED 3 or High bleeding risk as defined by Munich consensus document and CHA2DS2-VASc2)

Exclusion Criteria

New York Heart Association class IV congestive heart failure
Atrial septal defect or atrial septal repair or closure device
Single occurrence of atrial fibrillation
Cardioversion or ablation procedure planned within 30 days
Implanted mechanical valve prosthesis
Heart transplantation
Enrolled in another IDE or IND investigation of a cardiovascular device or an investigational drug
Pregnant or pregnancy is planned during the course of the investigation
Active infection of any kind
Severe chronic kidney insufficiency (CrCl< 30 ml/min)
Terminal illness with life expectancy < 1 yr
Echocardiographic exclusion criteria
Left ventricular ejection fraction < 20%
Intra-cardiac thrombus or dense spontaneous echo contrast as visualized by TEE within 2 days before implant
Significant mitral valve stenosis (ie, MV <1.5 cm2)
Complex aortic atheroma with mobile plaque of the descending aorta and/or aortic arch
Cardiac tumor
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