Abstract 25: Left Atrial Volume Index is Associated With Atrial Fibrillation and Recurrent Stroke in Embolic Stroke of Undetermined Source (ESUS)

Abstract

In ESUS, the relationship between atrial cardiopathy, occult AF and embolic stroke risk remains unclear. Studies suggest that left atrial volume index (LAVi) may be a better estimate of atrial cardiopathy than LA diameter. We explored LAVi as a marker of occult AF detection and ischemic stroke recurrence. Methods: From 2015-2017, consecutive ESUS patients diagnosed based on consensus criteria were studied. LAVi was measured using the Biplane Area-Length Method on TTE by trained cardiologists. Clinical outcomes measured were occult AF detection and ischemic stroke recurrence in a time-to-event analysis. Kaplan-Meier curves were constructed to compare outcomes in those with high versus low LAVi at optimized cut-off values. Results: 199 consecutive ESUS patients were followed up for 2.2±1.0 years. 9 patients were excluded due to technically inadequate views. Increased LAVi was associated with AF detection (36.63mL/m 2 ± 12.2 vs 26.93mL/m 2 ± 9.6) and stroke recurrence (32.13mL/m 2 ± 9.3 vs 27.23mL/m 2 ± 10.1). On multivariate regression adjusting for age, sex, hypertension and diabetes mellitus, LAVI was independently associated with AF detection (OR 1.08, CI 95% 1.03-1.14; p=0.003) and stroke recurrence (OR 1.05, CI 95% 1.01-1.10; p=0.026). Kaplan-Meier curves showed significant differences in occult AF (log-rank 8.67, p=0.003) and stroke recurrence (log-rank 5.31, p=0.021) between high (>27.7ml/m 2 ) and low LAVi (≤27.7ml/m 2 ) groups. Conclusion: Increased LAVi in ESUS patients was associated with AF detection and stroke recurrence, suggesting that this may be a useful echocardiographic marker to identify high-risk patients who may potentially benefit from anticoagulation.