(B-142) Antithrombotic Treatment after Left Atrial Appendage Occlusion in Older Atrial Fibrillation Patients

Monday, August 25, 2025

11:30 AM - 1:00 PM ET

Presenting Author(s)

Xiaojuan Liu, PhD

Brigham and Women's Hospital and Harvard Medical School, United States

Co-Author(s)

SS

Sebastian Schneeweiss, MD, ScD

Brigham and Women's Hospital and Harvard Medical School, United States
DS

Daniel E. Singer, MD

Massachusetts General Hospital and Harvard Medical School, United States
JA

Jerry Avorn, MD

Brigham and Women's Hospital and Harvard Medical School, United States
EH

E. Kevin Heist, MD, PhD

Massachusetts General Hospital and Harvard Medical School, United States
KL

Kueiyu Joshua Lin, MD, ScD, MPH

Brigham and Women's Hospital and Harvard Medical School, United States

Background: Left atrial appendage occlusion (LAAO) is an alternative to oral anticoagulants (OAC) for stroke prevention in nonvalvular atrial fibrillation (AF); however, real-world data on post-LAAO antithrombotic treatment patterns and adherence to the standardized treatment protocol remain limited.

Objectives: To characterize antithrombotic treatment patterns following LAAO and identify factors influencing adherence to the treatment protocol.

Methods: Using Optum claims data (2015-2024), we included 16304 AF patients (mean [SD] age = 78 [6]; 47% female; CHA2DS2-VASc score = 5.0 [1.5]) undergoing first-time LAAO, and divided into mutually exclusive subgroups based on initial concomitant antithrombotic therapy at implantation. OAC discontinuation was defined as a ≥60-day gap in supply, and prolonged OAC use was operationally defined as either (1) an OAC refill following a imaging assessment performed 30–90 days post-implantation, (2) OAC refill beyond 90 days post-implantation, regardless of imaging completion, or (3) occurrence of device-related thrombus, embolism, or peri-device leakage.

Results: Among LAAO recipients, 9844 (60%) received concomitant OAC and 3499 (10%) received P2Y12 inhibitor at implantation. Among OAC users, median duration of use was 54 days and 83% discontinued OAC by 6 months post-implantation. Imaging was performed in 11237 (69%) patients at 45 (±15) days, and only 23% patients followed the standard postprocedural protocol. Common deviation from the protocol included early OAC discontinued (31%), continued OAC use post-TEE (14%), and P2Y12 inhibitor initiated early or not initiated (14%). Prolonged OAC use was observed in 2,120 (13%) patients. Factors associated with a higher likelihood of prolonged OAC use included older age, Black race, kidney disease, AF-related procedures, and longer prior OAC use.

Conclusions: We observed a heterogeneous pattern of post-LAAO antithrombotic therapy and a moderate to low adherence to the LAAO postprocedural protocol. Further evaluation is warranted on the clinical impact of these treatment and adherence patterns.