Incremental Value of Left Atrial Global Longitudinal Strain for Prediction of Post Stroke Atrial Fibrillation in Patients with Acute Ischemic Stroke

Background: Atrial fibrillation (AF) is a well-established risk factor for stroke. Interestingly, ischemic stroke increases risk of incident AF in patients without prior diagnosed AF. For better risk stratification for post-stroke AF, we studied left atrial (LA) size and mechanical function using two-dimensional (2D) speckle tracking imaging in patients with acute ischemic stroke. Methods: A total of 227 patients (132 males, age $67{\pm}12$) with acute ischemic stroke without a history of AF underwent 2D transthoracic echocardiography and speckle tracking imaging for the assessment of LA volume index and global LA longitudinal strain (LALS). From clinical variables, the $CHA_2DS_2$-VASc score and National Institute of Health Stroke Scale (NIHSS) were calculated in each patient. Post-stroke AF was defined as newly diagnosed AF during the course after ischemic stroke. Results: Post-stroke AF occurred in 25 patients (11%). Patients with post-stroke AF were older and showed a higher tendency of $CHA_2DS_2$-VASc score, significantly higher log NIHSS, larger LA volume index and lower global LALS than those without. In multivariate analysis, global LALS was an independent predictor for post-stroke AF (hazard ratio 0.90, 95% confidence interval 0.83-0.97, p < 0.01) after controlling for confounding factors. Furthermore, global LALS provided incremental predictive value for post-stroke AF over the $CHA_2DS_2$-VASc score, NIHSS, and LA volume index. The global LALS < 14.5% better distinguished post-stroke AF (area under the curve 0.837, sensitivity 60%, specificity 95%, p < 0.01) than $CHA_2DS_2$-VASc score. Conclusion: Global LALS as a marker of LA mechanical function has incremental predictive value for post-stroke AF in patients with acute ischemic stroke.