Key Points:
- In 2021, the Amulet IDE study demonstrated that the novel Amulet left atrial appendage occluder device was noninferior to the standard Watchman device for stroke prevention in patients with nonvalvular atrial fibrillation. The study investigators have now pursued an analysis of the three year outcomes.
- The Amulet device continued to demonstrate safety and effectiveness through 3 years of follow up.
In 2021, the Amulet IDE study compared the Amulet left atrial appendage (LAA) occlusion device with the standard of care (Watchman device) in stroke reduction in nonvalvular atrial fibrillation (AF) patients. The study demonstrated that the Amulet occluder was noninferior to the Watchman in safety (at 12 months) and effectiveness in stroke reduction (at 18 months), but superior to the Watchman in degree of LAA occlusion (at 45 days). The study was then continued to examine the long-term efficacy and safety of the Amulet device. In a breaking presentation at the 2022 TCT Conference today, Dr. Dhanunjaya Lakkireddy (HCA Midwest, Kansas) and his team presented the three year outcomes of their study: “Amplatzer Amulet Left Atrial Appendage Occluder Randomized Controlled Trial,” or the Amulet IDE Study.
The AMULET IDE study (NCT02879448) was a prospective, randomized, multi-center active control trial conducted across 150 sites worldwide. Inclusion criteria comprised adults with nonvalvular AF with CHADS2 score ≥ 2 or a CHA2DS2-VASc score of ≥ 3 and an appropriate rationale to seek alternatives to oral anticoagulation; relevant exclusions included another clinical indication for anticoagulation or P2Y12 therapy, allergy to antiplatelets or warfarin, prior ASD/PFO repair or closure, intracardiac thrombus, or stroke within 90 days. A total of 1878 patients were randomized: 934 in the Amulet group, and 944 in the Watchman group. Of these, 721 survived and completed follow-up at the three-year visit in the Amulet group, compared to 659 patients in the Watchman group.
The purpose of this analysis was to assess the three years outcome of the AMULET IDE trial. There were no statistically significant differences in cardiovascular death, all-cause death, stroke, or major bleeding at three years between the two devices. Cardiovascular death and all-cause death were not significantly different but trended lower with Amulet compared to Watchman device ( 6.6% vs 8.5% and 14.6% vs 17.9 % respectively). The combined endpoint of stroke, systemic embolism, and CV death in the Amulet occluder group was 11.1% compared to 12.7% in the Watchman group. Major bleeding at 3 years was 16.1% in the Amulet group compared to 14.7% in the Watchman group. At three years, OAC usage was significantly higher in the Watchman device group than the Amulet group (7.3% vs 3.7%, p<0.01).
When discussing the clinical implications of the study at TCT, the authors stated: “The Amulet LAA occluder device continued to demonstrate safety and effectiveness through three years in the first large scale randomized head-to-head LAAO clinical trial [of patients with non-valvular atrial fibrillation].”