Early results of first versus second generation Amplatzer occluders for left atrial appendage closure in patients with atrial fibrillation

Background Transcatheter left atrial appendage (LAA) occlusion has been proven to be an effective treatment for stroke prophylaxis in patients with atrial fibrillation. For this purpose, the Amplatzer cardiac plug (ACP) was introduced. Its second generation, the Amulet, was developed for easier delivery, better coverage, and reduction of complications. Aim To investigate the safety and efficacy of first generation versus second generation Amplatzer occluders for LAA occlusion. Methods Retrospective analysis of prospectively collected data from the LAA occlusion registries of the Bern and Zurich university hospitals. Comparison of the last consecutive 50 ACP cases versus the first consecutive 50 Amulet cases in patients with non-valvular atrial fibrillation. For safety, a periprocedural combined endpoint, which is composed of death, stroke, cardiac tamponade, and bailout by surgery was predefined. For efficacy, the endpoint was procedural success. Results There were no differences between the two groups in baseline characteristics. The percentage of associated interventions during LAA occlusion was high in (78 % with ACP vs. 70 % with Amulet p = ns). Procedural success was similar in both groups (98 vs. 94 %, p = 0.61). The combined safety endpoint for severe adverse events was reached by a similar rate of patients in both groups (6 vs. 8 %, p = 0.7). Overall complication rate was insignificantly higher in the ACP group, which was mainly driven by clinically irrelevant pericardial effusions (24 vs. 14 %, p = 0.31). Death, stroke, or tamponade were similar between the groups (0 vs. 2 %, 0 vs. 0 %, or 6 vs. 6 %, p = ns). Conclusion Transcatheter LAA occlusion for stroke prophylaxis in patients with atrial fibrillation can be performed with similarly high success rates with first and second generations of Amplatzer occluders. According to this early experience, the Amulet has failed to improve results of LAA occlusion. The risk for major procedural adverse events is acceptable but has to be taken into account when selecting patients for LAA occlusion, a preventive procedure.