Abstract 4139996: Impact of Anticoagulation on Incidence of Cerebrovascular Accident After Epicardial Left Atrial Appendage Occlusion: A Retrospective Descriptive Analysis

Introduction: Atrial fibrillation is one of the most prevalent cardiac arrhythmias globally. In patients with atrial arrhythmias, the left atrial appendage (LAA) has been implicated in up to 90% of thrombus formation. Surgical LAA exclusion in addition to continued anticoagulation (AC) is recommended as a Class 1A recommendation, however true incidence of cerebrovascular accident (CVA) after LAA occlusion in the absence of continued AC is uncertain. Aims: This retrospective analysis aims to further explore the impact of AC on cerebrovascular accidents after epicardial LAA occlusion. Methods: A retrospective cohort analysis of individuals who underwent open cardiac surgery where LAA occlusion was performed. All patients who were 18 years or older at the time of admission were included and only those who died during the index admission were excluded. The study spanned from October 2015 to December 2022 at a tertiary healthcare system in the northeastern United States. The exposure is whether the patient was discharged on AC. The primary outcome was the incidence of CVA, and the secondary outcome was bleeding events, both at one-year post-index visit. Results: A total of 934 patients were included in the analysis with 471 (50.4%) being discharged without AC. Of those, 462 subjects had a history of atrial arrhythmia. A total of 5 subjects had a CVA, 3 of which were not discharged on anticoagulation. A total of 37 (4.0%) subjects had a major bleeding event, of which 21 (2.3%) were discharged on AC. (Table 1) A subgroup analysis of only those with a history of arrythmia revealed 327 (70.8%) patients in the subgroup were discharged on AC. Of this subgroup, the mean CHA2DS2-VASc score was 4.0 + 2.1 for those discharged on AC and 3.5 + 2.3 for those not discharged on AC. A total of 2 CVA occurred, both in the group not discharged on AC. Bleeding events occurred in 19 (4.1%) subjects, 14 (3.0%) of which were discharged on AC. (Table 2) Conclusion: The findings of this retrospective analysis suggest that AC after surgical LAA intervention may be beneficial in reducing the risk of CVA, particularly in patients with a history of atrial arrhythmias. This is, however, accompanied by a higher incidence of bleeding events. Ultimately, given the low number of outcomes recorded, larger multicenter prospective studies will need to be conducted to understand the true impact of AC on CVA and bleeding risks following surgical LAA intervention.