Rationale and design for AMPLATZER Amulet Left Atrial Appendage Occluder IDE randomized controlled trial (Amulet IDE Trial)

Background: Percutaneous closure of the left atrial appendage (LAA) is an alternative to chronic oral anticoagulation to reduce stroke risk in patients with non-valvular atrial fibrillation (NVAF). The Amplatzer™ Amulet™ LAA Occluder IDE Trial (Amulet 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 NVAF 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 endpoints included safety (composite of procedure-related complications, all-cause death, or major bleeding at 12 months) and effectiveness (composite of ischemic stroke or systemic embolism at 18 months) and the rate of LAA occlusion at 45 days. Pre-specified secondary endpoints 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 three primary endpoints. Results: A total of 1878 patients were enrolled. The Amulet occluder was noninferior to the Watchman device for the primary safety endpoint (14.5% vs. 14.7%; difference=-0.14, 95% CI, -3.42-3.13; p<0.001 for noninferiority). Major bleeding and all-cause death were similar between groups (10.6% vs 10.0% and 3.9% vs 5.1%, respectively). Procedure-related complications were higher for the Amulet occluder (4.5% vs. 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 endpoint (2.8% vs. 2.8%; difference=0.00, 95% CI, -1.55-1.55; p<0.001 for non-inferiority), and the composite of stroke, systemic embolism or cardiovascular/unexplained death (5.6% vs 7.7%, difference=-2.12, 95% CI, -4.45-0.21; p<0.001 for noninferiority). The rate of major bleeding was similar between groups (11.6% vs. 12.3%; difference=-0.71, 95% CI -3.72-2.31; p=0.32 for superiority). LAA occlusion was higher for the Amulet occluder compared with the Watchman device (98.9% vs. 96.8%; difference=2.03, 95% confidence interval [CI], 0.41-3.66; p<0.001 for noninferiority; p=0.003 for superiority). Conclusions: The Amulet occluder was non-inferior for safety and effectiveness of stroke prevention for NVAF compared with the Watchman device, and superior for LAA occlusion. Procedure-related complications were higher with the Amulet device and decreased with operator experience. Clinical Trial Registration: URL https://clinicaltrials.gov Unique Identifier NCT02879448

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Influence of Left Atrial Appendage Amputation on Natriuretic Peptides—A Randomized Controlled Trial

The Thoracic and Cardiovascular Surgeon ◽

10.1055/s-0039-1683955 ◽

2019 ◽

Author(s):

Philippe Grieshaber ◽

Borros Arneth ◽

Ferdinand Steinsberger ◽

Bernd Niemann ◽

Irina Oswald ◽

...

Keyword(s):

Heart Failure ◽

Natriuretic Peptide ◽

Left Atrial ◽

Detrimental Effect ◽

Left Atrial Appendage ◽

Controlled Trial ◽

Clinical Severity ◽

Atrial Appendage ◽

Baseline Levels

Background Closure or amputation of the left atrial appendage (LAA) is a common therapy for atrial fibrillation (AF). As the LAA is a hormone-producing organ, however, amputation is still somewhat controversial. We examined patients after surgical AF therapy with or without LAA amputation to determine the influence of LAA amputation on pro-atrial natriuretic peptide (proANP) and B-type natriuretic peptide (BNP) plasma levels and on clinical severity of heart failure. Methods Twenty-one consecutive patients were prospectively randomized to either undergo LAA amputation (n = 10) or no LAA amputation (n = 11) between 05/2015 and 10/2015. All patients underwent coronary and/or valve surgery and concomitant AF surgery with either cryoablation (n = 3) or radio frequency ablation (n = 17). ProANP and BNP levels were measured preoperatively and until 800 days postoperatively. Results Baseline proANP values were comparable between the groups (without LAA amputation: 4.2 ± 2.1 nmol/L, with LAA amputation: 5.6 ± 3.6 nmol/L). Postoperatively, proANP levels rose markedly in both groups. Even after LAA amputation, proANP levels remained elevated for 7 days postoperatively but fell to baseline levels at day 31 and remained on baseline level at 800 days postoperatively. ProANP levels in the LAA amputation group (5.8–9.7 nmol/L) were not significantly lower than in the group without LAA amputation (9.2–14.1 nmol/L; p = 0.357). BNP levels also rose after surgery in both groups until day 7. At 800 days after surgery, BNP levels were back at baseline levels in both groups. Clinical follow-up at 2 years postoperatively showed no difference in heart failure symptoms or need for heart failure medication between the groups. Conclusion In contrast to commonly held beliefs about the endocrine and reservoir functions of the LAA, there seems to be no clinically relevant detrimental effect of LAA amputation on natriuretic peptide levels and severity of heart failure until up to 2 years postoperatively.

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