Comparison of the efficacy and safety of new generation occluders watchman flx and amplatzer amulet in the long term according to the results of a clinical study

Abstract

Summary:

Relevance: Currently, there are no studies comparing the latest generation of occluders for endovascular isolation of the left atrial appendage. The only randomized study, SWISS-APERO, has significant limitations due to the presence of 22.7% of patients with implanted first-generation occluders. Therefore, assessing the effectiveness and safety of the latest generation occluders is a highly relevant task.

Methods: From 2021 to 2023, a prospective study was conducted at the Federal State Budgetary Institution "National Medical Research Center for Cardiovascular Surgery named after Academician E.N. Chazova" of the Ministry of Health of the Russian Federation, involving 100 patients. Patients were divided into two groups: Watchman FLX (n=49) and Amplatzer Amulet (n=51). The main goal of the study is to compare the safety and effectiveness of endovascular isolation of the left atrial appendage using the latest generation occluders Watchman FLX and Amplatzer Amulet in the long term.

Results: The average procedure time and LAA closure time in the Watchman FLX group was 66.22 minutes [59.95; 72.50], and in the Amplatzer Amulet group it was 69.45 minutes [61.36; 77.54], p=0.49. There were no statistically significant differences in the volume of used contrast agent: 260.2 [227.43; 292.98] in the Watchman FLX group vs. 237.25 [204.96; 269.55] in the Amplatzer Amulet group, p=0.32; the size of the left atrial appendage by angiography: 20.45 [19.68; 21.22] in the Watchman FLX group and 20.39 [19.29; 21.49] in the Amplatzer Amulet group, p=0.55; and the choice of occluder size: 25.61 [24.76; 26.47] in the Watchman FLX group vs. 24.41 [23.25; 25.58] in the Amplatzer Amulet group, p=0.25. However, there were statistical differences in the time of occlusion, where the average occlusion time was 16.95 minutes [95% CI: 15.70; 18.19] in the Watchman FLX group and 20.06 minutes [95% CI: 18.43; 21.68] in the Amplatzer Amulet group, p<0.05. Serious complications related to the procedure occurred more frequently in the Amplatzer Amulet group (10 (19.6%) vs. 6 (12.2%); p=0.041), including heart perforation in 6 patients (11%). In the Watchman FLX group, there were no complications, p=0.027. Frequent adverse hospital events were observed more often in the Amplatzer Amulet group: 5 (9.8%) vs. 1 (2%) in the Watchman FLX group, p=0.2. Bleeding from the access site occurred more frequently in the Amplatzer Amulet group (4 (7.8%)) compared to 1 (2%) in the Watchman FLX group, p>0.05. However, residual blood flow greater than 5 mm under transesophageal echocardiography control was higher in the Watchman FLX group (4 (8.1%)) than in the Amplatzer Amulet group, where it was not detected, p=0.054.

Conclusions: Occluders of the latest generation for endovascular LAA closure demonstrate high effectiveness in preventing ischemic stroke in patients with nonvalvular atrial fibrillation. The safety profile of Watchman FLX devices is higher, making them the preferred choice for such interventions.

Keywords: atrial fibrillation left atrial appendage isolation, next-generation occluders, Amplatzer Amulet, Watchman FLX.