AIMS: To evaluate safety and efficacy of left atrial appendage occlusion (LAAO) with the Amplatzer Cardiac Plug (ACP) or Amulet using Aspirin (ASA) alone as post-implant antithrombotic treatment.

METHODS AND RESULTS: Single-center, prospective, non-randomized study on LAAO with the ACP or Amulet in a consecutive cohort (n=110) treated by ASA alone post-implantation. Primary outcome was device-related thrombosis, while secondary outcomes were ischemic stroke or major bleeding. Clinical follow-up was conducted after 6 weeks and 12 months with TEE and cardiac CT. 107 patients were included for analysis. 3 patients were excluded due to mechanical valve prosthesis. CHA2DS2-VASc score was 4.4±1.6 and HAS-BLED 4.1±1.1. Successful implantation was obtained in all patients with a periprocedural complication rate of 4.6%. Median follow-up was 2.3 years, with a total of 265 patient-years. Device-related thrombosis was detected in 2/107 (1.9%) cases. Stroke occurred in 6/107 patients, with an annualized rate of 2.3%, which is a 61% risk reduction compared to the predicted rate. Annual risk of major bleeding was reduced by 57%.

CONCLUSIONS: LAAO with the ACP or Amulet was safely performed with ASA monotherapy after implantation without an increased risk of device-related thrombosis or stroke.