Left atrial function index in embolic stroke of undetermined source: A case-control study

Background & Objectives: Previous studies showed left atrial volume index (LAVi) is a precise surrogate of atrial cardiopathy and associated with new-onset atrial fibrillation and embolic stroke undetermined source (ESUS). Recent data suggest that the left atrial functional index (LAFi) is associated with the risk of developing AF recurrence. However, there was no study to show LAFi in ESUS. We aim to compare the performance of different surrogates of atrial cardiopathy (LAVi and LAFi) in a cohort of ESUS patients and healthy adults. Methods: Between Dec 2018 to Feb 2020, consecutive patients diagnosed with ESUS and normal healthy controls (>18 years) were included. Left atrial diameter (LAD), left atrial diameter index (LADi), LAVi and LAFi were measured by transthoracic echocardiogram under American Society of Echocardiography guidelines. Results: A total of 125 patients (43 controls and 82 ESUS patients) were compared. Significant differences of LADi, LAVi, and LAFi were detected between ESUS and control (p=0.04, p=0.002, and p=0.001, respectively). On adjustment for age, sex, hypertension, and diabetes mellitus, LADi and LAVi the association with ESUS and LAFi (aOR decrease, 0.928; 95% CI 0.882-0.976; p = 0.004) remained significant and LAD, LADi, and LAVi were not associated with ESUS in this analysis. Conclusions: LAFi may be a more comprehensive predictor of atrial cardiopathy as compared to LADi and LAVi in risk stratification of ESUS or cryptogenic stroke.