Abstract TP171: Impacts Of Left Atrial Size On The Short-term And Long-term Outcomes After Acute Ischemic Stroke

Abstract

Objectives: To investigate whether the left atrial diameter (LAD) was associated with stroke severity, outcome, long-term risk of stroke recurrence and mortality in patients with acute ischemic stroke. Methods: This study included acute ischemic stroke patients in the National Taiwan University Hospital Stroke Registry from 2015 to 2021. LAD was measured by transthoracic echocardiography and was divided by body surface area (indexed LAD) for standardization. Patients were further classified into normal (<2.3 cm/m 2 ), mildly (2.4-2.6), moderately (2.7-2.9), and severely (≥3.0) abnormal LAD. Short- term outcomes included stroke severity, stroke-in-evolution, and 3-month modified Rankin Scale (mRS), while long-term outcomes include recurrent ischemic stroke and mortality. Results: In total, 3952 patients (mean age 69.7±14.1, 43% female) were enrolled. The mean indexed LAD was 2.3±0.6 cm/m 2 . Patients in the abnormal LAD groups were older, had more female, higher NIHSS, more cardioembolic stroke, more likely to received reperfusion therapy, had higher proportion of stroke-in-evolution and higher 3-month mRS. In adjusted analyses, increased indexed LAD (per 1 cm/m 2 ) was associated with functional independence (mRS 0-2) at 3 months (odds ratio (OR) 1.59, 95% CI 1.28-1.98). During the follow-up of 3.12±2.16 years, 413 patients had recurrent ischemic stroke and 747 patients died. Increased indexed LAD was associated with mortality (hazard ratio (HR) 1.21, 95% CI 1.04-1.40), but not recurrent ischemic stroke (HR 1.07, 95% CI 0.86-1.32). In the cryptogenic stroke subgroup, severely abnormal LAD was associated with recurrent ischemic stroke (HR 2.69, 95% CI 1.23-5.88). In the AF subgroup, patients with pre-stroke oral anticoagulant use had larger indexed LAD (2.9±0.6 vs 2.6±0.6), but they had lower initial NIHSS at (8 vs 10) and were more likely to achieve functional independence (OR 1.55, 95% CI 1.08-2.24). Conclusion: In patients with acute ischemic stroke, left atrial enlargement is associated with higher probability of functional independence at 3 months, but higher risk of long-term mortality. Despite having larger left atrial size, pre-stroke oral anticoagulant use might be associated with better outcome in patients with atrial fibrillation.