Abstract Body (Do not enter title and authors here): Introduction
Atrial fibrillation (A fib) is the most common arrhythmia affecting 1-2% of the general population. A fib is a well-established risk factor for ischemic strokes. In patients with nonvalvular A fib, the majority of embolic strokes are caused by thrombi development in the left atrial appendage. Systemic anticoagulation (AC) is effective in reducing stroke risk in patients with A fib. However, bleeding complications and medication nonadherence are barriers to effective AC. In these patients, left atrial appendage occlusion (LAAO) act as a form of nonpharmacologic treatment.

Methods
We completed a retrospective descriptive study evaluating patients with a fib undergoing either open left atrial appendage closure or percutaneous occlusion. Patients were selected from the HCA database (Jan 2021-Jul 2023). ICD 10 codes were used to identify patients with documented a fib. Procedure ICD codes were used to identify patients that underwent percutaneous LAAO. Patients with documented STEMI, left ventricular thrombus, mechanical mitral or aortic valve replacement were excluded. 5,661 underwent percutaneous closure. Stroke readmissions were evaluated at 45, 90, and 180 days. Chi-square was used to evaluate for statistically significant differences.

Results
Of the 5,661 patients 40 developed a stroke within 45 days, 38 within 90 days, and 26 within 180 days (P=.19) The average patient age was 76.1 years with STD 7.86. There were 2438 females and 3223 males.

Discussion
Stroke occurrence was similar by day 90 as day 45. There was no statistical difference in stroke by day 180; however, the trend suggests a larger drop off in stroke readmission rates after day 90. Perhaps with a larger study, a significant effect may be detected. Currently AC is only recommended for 60 days post procedure. With clinical significance, future studies may be warranted to evaluate bleeding incidence during post procedure AC and the utility of extending therapy to 90 days.