Description of a National Cohort of Patients With Left Atrial Appendage Occlusion Devices

Background Stroke is a known complication of atrial fibrillation. To avoid anticoagulation therapy, left atrial appendage occlusion (LAAO) devices are often placed in patients. Objective This study, via a national cohort of patients, sought to describe the risks associated with LAAO. Methods Data used in this study came from Epic Cosmos, a dataset created in collaboration with a community of Epic health systems representing more than 296 million patient records from all 50 states, Washington D.C., Lebanon, and Saudi Arabia. Using this dataset, we assembled a cohort of patients who had an LAAO placed. Demographic information was gathered to risk-stratify via the Congestive heart failure, Hypertension, Age ≥75 years, Diabetes mellitus, Stroke, Vascular disease, Age 65-74 years, Sex category (CHA₂DS₂-VASc) score. Diagnosis of stroke was made using visits with that diagnosis after LAAO placement. Descriptive statistics and hazard ratios were calculated. This cohort was compared to previously published ones. Results The study cohort assembled consisted of 51,682 patients who underwent implantation of an LAAO from 2021 to 2023. The average age was significantly higher than previously published (p < 0.001), as was the risk of stroke. CHA₂DS₂-VASc of 7 or greater was associated with elevated risk of stroke after LAAO. For CHA₂DS₂-VASc of 7-9, the hazard ratio ranged from 4.88-6.32, with significant 95% confidence intervals. Conclusions This cohort suggests that the risk of stroke after LAAO implantation is higher than previously reported, though findings are limited by their retrospective nature. Patients with elevated CHA₂DS₂-VASc scores may require additional anticoagulation therapy to reduce the statistically significant increased risk of stroke. CHA₂DS₂-VASc scores, in this cohort, appear to stratify patients' stroke risk after LAAO placement.