The dual-seal Amplatzer Amulet Left Atrial Appendage Occluder continued to show superior closure at 12 months compared to the Watchman Left Atrial Appendage Closure Device, which uses a single occlusive mechanism, according to new trial data. Dhanunjaya Lakkireddy, MD, of the Kansas City Heart Rhythm Institute, presented the results of the Amulet Investigational Device Exemption trial Friday at Transcatheter Cardiovascular Therapeutics (TCT) 2021 in Orlando, Florida. The 45-day results, which Lakkireddy presented in August at the European Society of Cardiology 2021 virtual congress, also showed the superior closure with Amulet (Abbott Medical) as compared to Watchman (Boston Scientific). Those earlier results also showed that Amulet was noninferior to Watchman with respect to safety and effectiveness in patients with non-valvular atrial fibrillation (AF). Limited data exist for long-term analysis of peri-device leaks (PDL). Therefore, the results presented Friday compared 12-month PDL in Amulet and Watchman in patients with non-valvular AF who are at high risk of stroke. The Amulet IDE trial randomized 1,878 patients to receive the Amulet (n=903) or Watchman (n=885). At 12 months, 673 Amulet patients and 618 Watchman patients had transesophageal echocardiograms (TEEs) available for assessment. Of the missing TEEs, 64 were not performed and 100 were not evaluable in the Amulet arm, and 90 were not performed and 85 were not evaluable in the Watchman arm. At 45 days, 11% of Amulet patients had moderate or greater PDL, compared to 26% of Watchman patients (p<0.001). At 12 months, the rates were 10% in the Amulet group and 22% in the Watchman group (p<0.001). PDL rates were comparable between the groups from day 45 to 365. “Superiority of closure of the Amulet [LAA] occluder to the Watchman device at 45 days was durable at 12 months, allowing patients to remain off oral anticoagulants,” Lakkireddy said in his presentation Friday. “The Amulet occluder offers immediate and durable closure to reduce the risk of stroke and freedom from long-term oral anticoagulants.” Lakkireddy acknowledged limitations to this analysis, including that it did not examine the clinical impact of the difference in closure rates between the devices and that a large number of patients were either lost to follow-up or had images that were not available or interpretable. The Amulet IDE trial was funded by Abbott Medical.