Left Atrial Strain for Risk Stratification of Later‐Detected Atrial Fibrillation After Acute Ischemic Stroke

Purpose Atrial fibrillation (AF) may be detected after acute ischemic stroke (AIS) even when it is not identified during the initial stroke evaluation. This study evaluated the association between left atrial strain (LAS) parameters measured by routine echocardiography and later‐detected AF after AIS. Methods This retrospective study included 490 patients with AIS without prior or concurrent AF who underwent speckle‐tracking LAS analysis. Later‐detected AF was defined as AF newly documented more than 7 days after the index stroke. Clinical and echocardiographic parameters were compared according to later‐detected AF status, and associations were evaluated using logistic regression. Exploratory receiver operating characteristic (ROC) analysis assessed the discriminatory ability of the LAS parameters. Results Over a median follow‐up of 30.6 months, later‐detected AF was observed in 23 patients (4.7%). Patients with later‐detected AF had lower LA reservoir strain (LASr) and less negative LA contractile strain (LASct) than those without AF (LASr: 22.4% ± 5.3% vs. 29.1% ± 8.9%; LASct: −11.3% ± 4.2% vs. −16.3% ± 5.5%; both p < 0.001). In multivariable models adjusted for CHA 2 DS 2 ‐VA score and LA volume index (LAVI), both LASr and LASct remained associated with later‐detected AF (LASr: odds ratio [OR], 0.93; 95% confidence interval [CI], 0.87–0.98; p = 0.010; LASct: OR, 0.86; 95% CI, 0.78–0.93; p < 0.001). ROC analysis showed modest discriminatory ability for LASr, LASct, and LAVI. Conclusion LASr and LASct were associated with later‐detected AF after AIS and may help identify patients who may warrant closer rhythm surveillance when extended monitoring is limited.