TY - JOUR

T1 - Amplatzer Amulet Left Atrial Appendage Occluder Versus Watchman Device for Stroke Prophylaxis (Amulet IDE)

T2 - A Randomized, Controlled Trial

AU - Lakkireddy, Dhanunjaya

AU - Thaler, David

AU - Ellis, Christopher R.

AU - Swarup, Vijendra

AU - Sondergaard, Lars

AU - Carroll, John

AU - Gold, Michael R.

AU - Hermiller, James

AU - Diener, Hans Christoph

AU - Schmidt, Boris

AU - MacDonald, Lee

AU - Mansour, Moussa

AU - Maini, Brijeshwar

AU - O'Brien, Laura

AU - Windecker, Stephan

PY - 2021

Y1 - 2021

N2 - BACKGROUND: Percutaneous closure of the left atrial appendage (LAA) is an alternative to chronic oral anticoagulation to reduce stroke risk in patients with nonvalvular atrial fibrillation. The Amulet IDE trial (Amplatzer Amulet Left Atrial Appendage Occluder IDE Trial) was designed to evaluate the safety and effectiveness of the dual-seal mechanism of the Amulet LAA occluder compared with the Watchman device. METHODS: Patients with nonvalvular atrial fibrillation at increased risk of stroke were randomly assigned (1:1) to undergo percutaneous implantation of a LAA occluder with the Amulet occluder or Watchman device. The primary end points included safety (composite of procedure-related complications, all-cause death, or major bleeding at 12 months), effectiveness (composite of ischemic stroke or systemic embolism at 18 months), and the rate of LAA occlusion at 45 days. Prespecified secondary end points included a composite of all stroke, systemic embolism, or cardiovascular/unexplained death at 18 months, major bleeding at 18 months, and superiority test of the 3 primary end points. RESULTS: A total of 1878 patients were enrolled. The Amulet occluder was noninferior to the Watchman device for the primary safety end point (14.5% versus 14.7%; difference=-0.14 [95% CI, -3.42 to 3.13]; P<0.001 for noninferiority). Major bleeding and all-cause death were similar between groups (10.6% versus 10.0% and 3.9% versus 5.1%, respectively). Procedure-related complications were higher for the Amulet occluder (4.5% versus 2.5%), largely related to more frequent pericardial effusion and device embolization. The Amulet occluder was noninferior to the Watchman device for the primary effectiveness end point (2.8% versus 2.8%; difference=0.00 [95% CI, -1.55 to 1.55]; P<0.001 for noninferiority), and the composite of stroke, systemic embolism, or cardiovascular/unexplained death (5.6% versus 7.7%, difference=-2.12 [95% CI, -4.45 to 0.21]; P<0.001 for noninferiority). The rate of major bleeding was similar between groups (11.6% versus 12.3%; difference=-0.71 [95% CI, -3.72 to 2.31]; P=0.32 for superiority). LAA occlusion was higher for the Amulet occluder than for the Watchman device (98.9% versus 96.8%; difference=2.03 [95% CI, 0.41-3.66]; P<0.001 for noninferiority; P=0.003 for superiority). CONCLUSIONS: The Amulet occluder was noninferior for safety and effectiveness of stroke prevention for nonvalvular atrial fibrillation compared with the Watchman device and superior for LAA occlusion. Procedure-related complications were higher with the Amulet occluder and decreased with operator experience. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02879448.

AB - BACKGROUND: Percutaneous closure of the left atrial appendage (LAA) is an alternative to chronic oral anticoagulation to reduce stroke risk in patients with nonvalvular atrial fibrillation. The Amulet IDE trial (Amplatzer Amulet Left Atrial Appendage Occluder IDE Trial) was designed to evaluate the safety and effectiveness of the dual-seal mechanism of the Amulet LAA occluder compared with the Watchman device. METHODS: Patients with nonvalvular atrial fibrillation at increased risk of stroke were randomly assigned (1:1) to undergo percutaneous implantation of a LAA occluder with the Amulet occluder or Watchman device. The primary end points included safety (composite of procedure-related complications, all-cause death, or major bleeding at 12 months), effectiveness (composite of ischemic stroke or systemic embolism at 18 months), and the rate of LAA occlusion at 45 days. Prespecified secondary end points included a composite of all stroke, systemic embolism, or cardiovascular/unexplained death at 18 months, major bleeding at 18 months, and superiority test of the 3 primary end points. RESULTS: A total of 1878 patients were enrolled. The Amulet occluder was noninferior to the Watchman device for the primary safety end point (14.5% versus 14.7%; difference=-0.14 [95% CI, -3.42 to 3.13]; P<0.001 for noninferiority). Major bleeding and all-cause death were similar between groups (10.6% versus 10.0% and 3.9% versus 5.1%, respectively). Procedure-related complications were higher for the Amulet occluder (4.5% versus 2.5%), largely related to more frequent pericardial effusion and device embolization. The Amulet occluder was noninferior to the Watchman device for the primary effectiveness end point (2.8% versus 2.8%; difference=0.00 [95% CI, -1.55 to 1.55]; P<0.001 for noninferiority), and the composite of stroke, systemic embolism, or cardiovascular/unexplained death (5.6% versus 7.7%, difference=-2.12 [95% CI, -4.45 to 0.21]; P<0.001 for noninferiority). The rate of major bleeding was similar between groups (11.6% versus 12.3%; difference=-0.71 [95% CI, -3.72 to 2.31]; P=0.32 for superiority). LAA occlusion was higher for the Amulet occluder than for the Watchman device (98.9% versus 96.8%; difference=2.03 [95% CI, 0.41-3.66]; P<0.001 for noninferiority; P=0.003 for superiority). CONCLUSIONS: The Amulet occluder was noninferior for safety and effectiveness of stroke prevention for nonvalvular atrial fibrillation compared with the Watchman device and superior for LAA occlusion. Procedure-related complications were higher with the Amulet occluder and decreased with operator experience. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02879448.

KW - anticoagulants

KW - atrial appendage

KW - atrial fibrillation

KW - prevention & control

KW - stroke

U2 - 10.1161/CIRCULATIONAHA.121.057063

DO - 10.1161/CIRCULATIONAHA.121.057063

M3 - Journal article

C2 - 34459659

AN - SCOPUS:85118572388

VL - 144

SP - 1543

EP - 1552

JO - Circulation

JF - Circulation

SN - 0009-7322

IS - 19

ER -