Association of Left Atrial Echocardiographic Indices With Atrial Fibrillation in Cryptogenic Stroke: A Systematic Review and Meta-Analysis.

INTRODUCTION

Atrial fibrillation (AF) is linked with cardioembolism and serves as an important underlying etiology of cryptogenic stroke (CS). Left atrial (LA) indices have been investigated as markers of asymptomatic AF among CS survivors. We aimed to evaluate the association between LA indices and newly detected AF following CS.

METHODS

A literature search through PubMed, Scopus, Cochrane Library, and Europe PMC identified observational studies enrolling CS patients without prior AF who were monitored for AF. Left atrial volume index (LAVI), left atrial reservoir strain (LASr), and left atrial contractile strain (LASct) were assessed using echocardiography at admission and compared between patients with or without new-onset AF. Subgroup analysis was conducted for patients with embolic stroke of undetermined source (ESUS). Pooled mean differences with 95% confidence intervals (CIs) were measured using the random-effects model.

RESULTS

Twenty-three studies comprising 3475 participants (AF = 1050; non-AF = 2425) were included in the analysis, with 11 studies assessing exclusively ESUS patients. Meta-analysis demonstrated significantly higher LAVI (MD 7.76 mL/m2; 95% CI 6.04 to 9.49; I2 = 72%; p < 0.00001) and significantly lower LASr (MD -8.07%; 95% CI -10.13 to -6.01; I2 = 88%; p<0.00001) and LASct (MD -5.26%; 95% CI -6.69 to -3.83; I2 = 86%; p < 0.00001) in CS patients who developed AF compared with those who did not. Similarly, significantly higher LAVI and lower LASr and LASct were observed in ESUS patients with new-onset AF.

CONCLUSION

In conclusion, AF occurrence is associated with higher LAVI and lower LASr and LASct among CS patients, suggesting an association between LA function and newly detected AF.