Left Atrial Appendage Occlusion Tied to Lower Ischemic Stroke Risk in AF

Compared with continued oral anticoagulation therapy alone, left atrial appendage occlusion is linked to a lower risk for ischemic stroke in patients with nonvalvular atrial fibrillation (AF) plus a prior thromboembolic event, according to study results published in JAMA Neurology.

Researchers conducted a cohort study to compare percutaneous left atrial appendage occlusion with continued oral anticoagulation therapy alone as prevention measures against subsequent stroke in patients with AF who had a previous thromboembolic event despite taking oral anticoagulation therapy. Patients in the STR-OAC LAAO cohort who underwent left atrial appendage occlusion between 2010 and 2022 and had a follow-up longer than 3 months were propensity score-matched 1:1 to patients in a control cohort who had nonvalvular AF, recent ischemic stroke or transient ischemic attack, and follow-up longer than 3 months who were taking oral anticoagulation therapy prior to the initial event. The primary outcome was time to first ischemic stroke. Logistic regression was used in statistical analysis.

A total of 433 patients (mean age, 71.8; men, 61%) across 21 sites received left atrial appendage occlusion treatment and were matched with 433 patients (mean age, 72.7; men, 64%) in the control cohort. The majority of index events in both cohorts was ischemic stroke.

Ischemic stroke occurred 16 times in the STR-OAC LAAO cohort and 34 times in the control cohort over the course of the 2-year follow-up. Annualized event rates for ischemic stroke were 2.8% and 8.9% in the STR-OAC LAAO and control cohorts, respectively. There were significant between-group differences in the time to first ischemic stroke (hazard ratio [HR], 0.33; 95% CI, 0.19-0.58; P <.001).

Time to first event analyses for ischemic stroke and all-cause death favored the STR-OAC LAAO vs control cohort (HR, 0.48; 95% CI, 0.32-0.72; P <.001).

Intracranial hemorrhage occurred 2 and 7 times in the STR-OAC LAAO and control cohorts, respectively (HR, 0.23; 95% CI, 0.05-1.16; P =.05).

Relative risk reductions in the STR-OAC LAAO cohort were 79% for ischemic stroke, 54% for ischemic stroke/transient ischemic attack/systemic embolism, and 73% for nonprocedural major bleeding events.

Sensitivity analyses revealed that risk for ischemic stroke was lower in the left atrial appendage occlusion vs control group when excluding patients with inadequate oral anticoagulation therapy before the index event (HR, 0.28; 95% CI, 0.15-0.53) and when only including patients with ischemic stroke as the index event (HR, 0.31; 95% CI, 0.16-0.62).

Study limitations include potential confounders and heterogeneity.

“In patients with nonvalvular AF with a prior thromboembolic event despite taking oral anticoagulation therapy, left atrial appendage occlusion was associated with a lower risk of ischemic stroke compared with continued oral anticoagulation therapy alone,” the study authors concluded.

Disclosure: Multiple study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of the authors’ disclosures.