Patterns of antithrombotic treatment after left atrial appendage occlusion

Left atrial appendage occlusion (LAAO) is an alternative to oral anticoagulants (OACs) for stroke prevention in atrial fibrillation (AF); however, data on post-LAAO antithrombotic patterns remain limited.

This study aimed to characterize post-LAAO antithrombotic patterns in routine clinical practice.

Patients with AF aged ≥65 years undergoing first-time LAAO were included from Optum claims data (2015-2024). OAC discontinuation was defined as an absence of refill in 60 days. Prolonged OAC use was operationally defined as an OAC refill after an imaging evaluation performed 30-90 days after implantation or an OAC refill beyond 90 days after implantation.

Among 16,304 LAAO recipients (mean age 78; 47% female), 9844 (60%) received an OAC and 3499 (10%) received a P2Y12 inhibitor (either alone or with an OAC) after implantation. At 6 months after the procedure, 6.5% of patients remained on OAC and 39% remained on P2Y12 inhibitors. Among OAC users, the median duration of use was 54 days and 83% discontinued by 6 months. Among OAC users with an imaging assessment by 45 days (n = 6856), 39% of patients followed the recommended treatment protocol; common deviations included early OAC discontinuation (31%) and continued OAC use beyond 6 months (11%). Prolonged OAC use was observed in 2030 patients (12.5%). Factors associated with prolonged OAC use included black race, kidney disease, AF ablation, cardioversion, and longer pre-LAAO OAC use.

We observed heterogeneous patterns of post-LAAO antithrombotic therapy, with a substantial proportion of patients remaining on OAC or P2Y12 inhibitors beyond suggested durations, indicating an opportunity to improve practice and outcomes.