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Design and Rationale of the Swiss-Apero Randomized Clinical Trial: Comparison of Amplatzer Amulet vs Watchman Device in Patients Undergoing Left Atrial Appendage Closure


Residual or newly acquired leaks are routinely appraised after left atrial appendage closure (LAAC). The Watchman and the Amulet are the two most frequently used devices for LAAC but no randomized study has so far assessed their comparative leak rates after intervention. The “Comparison of Amplatzer Amulet vs Watchman devices in patients undergoing left atrial appendage closure” (Swiss-Apero, NCT03399851) is an academic-sponsored multicenter, randomized clinical trial comparing Amulet versus Watchman/FLX devices among patients undergoing a clinically indicated LAAC. The study is designed to assess the superiority of Amulet vs. Watchman/FLX in terms of leaks detected by cardiac computed tomography angiography (CCTA) at 45 days (primary endpoint) and 13 months (secondary endpoint) after intervention by an imaging Core Laboratory. The Swiss-Apero study is the first randomized clinical trial comparing Amulet and Watchman/FLX with respect to the prevalence of post-procedural leak as assessed with CCTA.

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Amplatzer cardiac plug


Acute myocardial infarction


Acute kidney injury


Bleeding Academic Research Consortium


Coronary artery bypass graft


Cardiac computed tomography angiography


Clinical Events Committee


Congestive heart failure


Central nervous system


Computed tomography




Device-related thrombus


12-lead electrocardiogram


Hounsfield unit


Intracardiac echocardiography


Imaging core lab


Intra device leak


Instructions for use


Left atrium


Left atrial appendage


Left atrial appendage closure


Left bundle branch block


Myocardial infarction


MIxed leak


Magnetic resonance imaging


Non-vitamin-K antagonist oral anticoagulants


Non patent left atrial appendage


Patent left atrial appendage


Patent left atrial appendage with no visible leak


Percutaneous coronary intervention


Peridevice leak


Transesophageal echocardiography


Upper range limit


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This study is supported by local available funding and from a research grant from St. Jude Medical/Abbott, Nathan Lane North Plymouth, MN, USA

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Corresponding author

Correspondence to Marco Valgimigli.

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Human Subjects/Informed Consent Statement

All procedures followed are in accordance with the ethical standards of the responsible committee on human experimentation (“Kantonale-Ethikkommission-Bern”-Switzerland; “Sud-Mediterranee-IV”-France; Erasme-ULB-Belgium; IRCCS-SanRaffaele-Italy) and with the Helsinki Declaration of 1975, as revised in 2000. Informed consent is obtained from all patients previous to being included in the study.


FDM reports consultancies and paid expert testimonies from Abbott and Boston-Scientific. AA is a proctor and consultant for Abbott and Boston-Scientific. NM reports personal fees and other from Abbott and St. Jude-Medical, grants from Boston-Scientific, during the conduct of the study; grants and personal fees from BMS-Pfizer, personal fees from Bayer-Health-Care, Boehringer-Ingelheim, AstraZeneca, outside the submitted work. FA is consultant for Boston-Scientific. ET reports personal fees from Abbott for proctoring. XI is a proctor for Boston-Scientific and Abbott, he is a consultant for Philips-Health-Care. PV reports personal fees from AstraZeneca, Bayer-Health-Care, Terumo, and Daiichi-Sankyo outside the submitted work. UF reports grants from Medtronic, other from Medtronic, Stryker and CSL-Behring, outside the submitted work. FB is proctor for Abbott, Boston-Scientific and Medtronic; he reports consultancies from Terumo and Meril. SW reports research and educational grants to the institution from Abbott, Amgen, BMS, Bayer, Boston-Scientific, Biotronik, Cardinal-Health, CSL-Behring, Daiichi-Sankyo, Edwards-Lifesciences, Johnson&Johnson, Medtronic, Querbet, Polares, Sanofi, Terumo, Sinomed. LR reports research grants to institution by Abbott-Vascular, Boston-Scientific, Biotronik, Heartflow, Sanofi, Regeneron. He reports speaker/consultation fees by Abbott-Vascular, Amgen, AstraZeneca, CSL-Behring, Canon, Occlutech, Sanofi, Vifor. MV has received grants and/or personal fees from AstraZeneca, Terumo, Alvimedica/CID, Abbott-Vascular, Daiichi-Sankyo, Opsens, Bayer, CoreFLOW, Idorsia-Pharmaceuticals-Ltd., Universität Basel Department Klinische Forschung, Vifor, Bristol-Myers-Squibb-SA, iVascular, and Medscape. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.

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Galea, R., De Marco, F., Aminian, A. et al. Design and Rationale of the Swiss-Apero Randomized Clinical Trial: Comparison of Amplatzer Amulet vs Watchman Device in Patients Undergoing Left Atrial Appendage Closure. J. of Cardiovasc. Trans. Res. (2021).

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  • Left atrial appendage closure
  • Randomized clinical trial
  • Cardiac computed tomography angiography
  • Amulet
  • Watchman
  • Watchman FLX