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Randomized Controlled Trial
. 2025 Jul 8;86(1):3-14.
doi: 10.1016/j.jacc.2025.03.535.

3-Year Clinical Outcomes Comparing the Amulet vs Watchman FLX for Left Atrial Appendage Closure in Patients With Atrial Fibrillation: Results From the SWISS-APERO Randomized Clinical Trial

Roberto Galea  1 , Federico De Marco  2 , Adel Aminian  3 , Nicolas Meneveau  4 , Konstantina Chalkou  5 , Frederic Anselme  6 , Christoph Gräni  7 , Anna Franzone  8 , Pascal Vranckx  9 , Urs Fischer  10 , Marco Valgimigli  11 , Lorenz Räber  12
Affiliations
Randomized Controlled Trial

3-Year Clinical Outcomes Comparing the Amulet vs Watchman FLX for Left Atrial Appendage Closure in Patients With Atrial Fibrillation: Results From the SWISS-APERO Randomized Clinical Trial

Roberto Galea et al. J Am Coll Cardiol. .

Abstract

Background: No study thus far has compared Amulet with Watchman FLX for clinical outcomes beyond 1 year after percutaneous left atrial appendage closure (LAAC).

Objectives: The goal of this study was to compare Amulet and Watchman FLX in terms of 3-year clinical outcomes.

Methods: In the investigator-initiated SWISS-APERO (Comparison of Amplatzer Amulet and Watchman Device in Patients Undergoing Left Atrial Appendage Closure) trial, patients with atrial fibrillation and high bleeding risk undergoing LAAC were randomly assigned (1:1) to receive Amulet or Watchman/FLX across 8 centers. Study endpoint included the composite of cardiovascular death, stroke, transient ischemic attack, or systemic embolism at 3 years. Analyses were repeated in the as-treated (AT) and per-protocol (PP) populations.

Results: Of the 221 patients randomized to treatment, 220 completed LAAC and 3 patients randomized to receive the Amulet device received the Watchman FLX device. The follow-up rate at 3 years was 96.4% in the Amulet group and 97.3% in the Watchman group. The composite ischemic endpoint occurred numerically less frequently in the Amulet group compared with the Watchman group (18.2% vs 31.0%; HR: 0.58; 95% CI: 0.33-1.03; P = 0.06). In both the AT (17.0% vs 31.1%; HR: 0.53; 95% CI: 0.30-0.96; P = 0.035) and PP (16.2% vs 29.2%; HR: 0.54; 95% CI: 0.29-1.00; P = 0.049) populations, the composite ischemic endpoint was significantly lower in the Amulet group compared with the Watchman group.

Conclusions: At 3 years after LAAC, there was no significant difference in the ischemic risk between the Amulet and the Watchman FLX groups. The lower occurrence of the ischemic composite endpoint observed in the Amulet group in both the AT and PP analyses is hypothesis generating and emphasizes the need for further studies. (Comparison of Amplatzer Amulet and Watchman Device in Patients Undergoing Left Atrial Appendage Closure [SWISS-APERO]; NCT03399851).

Keywords: Amulet; Watchman FLX; atrial fibrillation; left atrial appendage closure; long-term follow-up; stroke.

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Conflict of interest statement

Funding Support and Author Disclosures The SWISS-APERO trial was partially supported by a research grant from Abbott. The funding company was not involved in the study processes, including site selection, study conduct, data collection, data analysis, and writing or reviewing of the manuscript. Dr Galea is a proctor and consultant for Abbott; has received speaking honorarium from Boston Scientific; and has received research grants from the Swiss Heart Foundation. Dr De Marco has received consultancies and paid expert testimonies from Abbott and Boston Scientific. Dr Aminian is a proctor and consultant for Abbott and Boston Scientific. Dr Meneveau has received grants and personal fees from Bayer Healthcare, BMS Pfizer, and Abbott; and has received personal fees from AstraZeneca and Terumo, outside the submitted work. Dr Chalkou has received a previous grant from the EU’s Horizon 2020 Research and Innovation Program (under grant agreement number 825162); has received support for attending meetings or travel from ECTRIMS; and was employed by Johnson & Johnson in a summer PhD internship and by the Department of Clinical Research, University of Bern, which has a staff policy of not accepting honoraria or consultancy fees (however, Department of Clinical Research is involved in the design, conduct, or analysis of clinical studies funded by not-for-profit and for-profit organizations; in particular, pharmaceutical and medical device companies provide direct funding to some of these studies). Dr Gräni has received funding from the Swiss National Science Foundation, Innosuisse, CAIM Foundation, GAMBIT Foundation, and Novartis Foundation, outside of the submitted work. Dr Vranckx has received honoraria from the Baim Institute for Clinical Research (formerly Harvard Clinical Research Institute for the AEGIS-II [sponsored by CSL Behring]), the LIBREXIA trial (sponsored by Janssen–Bristol Myers Squibb Alliance), and the European Heart Journal–Acute Cardiovascular Care (Editor in Chief). Dr Fischer has received grants from Medtronic; and other from Medtronic, Stryker, and CSL Behring, outside the submitted work. Dr Valgimigli 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. Dr Räber has received research grants to institution by Abbott Vascular and Structural, Boston Scientific, Biotronik, HeartFlow, Sanofi, Swiss Science Foundation, Regeneron; and has received speaker/consultation fees by Abbott Vascular and Structural, Amgen, AstraZeneca, CSL Behring, Canon, Novo Nordisk, Occlutech, and Sanofi. Drs Anselme and Franzone have reported that they have no relationships relevant to the contents of this paper to disclose.

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