Left Atrial Dilation and Risk of One-Year Readmission after Embolic Stroke of Undetermined Source.

Background: Structural left atrial and ventricular abnormalities on the electrocardiogram (ECG) and transthoracic echocardiogram (TTE) at the time of ischemic stroke have been associated with morbidity and mortality. Yet, the prognostic impact of the same in embolic stroke of undetermined source (ESUS), a relevant subtype of ischemic stroke with a unique pathophysiology, has not been well studied to date. Our aim was to assess the predictive impact of left atrio-ventricular ECG and TTE abnormalities on one-year hospital readmission after ESUS from an ongoing single center prospective stroke registry in the U.S.

Methods: We identified 369 ESUS patients who had at least 1 year of complete follow-up between 2013 and 2018. We examined the association of abnormal left atrio-ventricular findings on ECG and TTE, as well as basic demographic and clinical characteristics, measured at index admission with time to 1-year hospital readmission using Kaplan-Meier curves, log-rank tests, and Cox proportional hazards regression.

Results: Recurrent ischemic stroke and cardiovascular causes constituted 60% of all readmissions. Patients with left atrial dilation on TTE were more likely to readmitted within 1 year (HR 1.51; 95% CI, 1.04-2.21). Bundle branch block, pathologic Q-wave, and troponin elevation curves diverged, but were not significantly associated with readmission (log-rank p=0.34, p=0.08, p=0.42, respectively).

Conclusions: Following ESUS, left atrial dilation on TTE was associated with 1-year overall hospital readmission, of which cardiovascular and cerebrovascular ischemic events, and heart failure were a notable proportion. Our data support ongoing studies of atrial cardiopathy in ESUS patients.