Objective <p>To investigate the predictive value of left ventricular (LV) global longitudinal strain (GLS) for mid-term major adverse cardiovascular events (MACE) in patients with atrial fibrillation (AF) complicated by acute myocardial infarction (AMI).</p> Methods <p>This single-center cohort study consecutively enrolled 200 patients with AF complicated by AMI, all of whom completed a 12-month follow-up. GLS was measured by two-dimensional speckle-tracking echocardiography within 72&#xa0;h after admission. Patients were divided into a high-GLS group and a low-GLS group according to the median GLS value. Baseline characteristics and the incidence of mid-term MACE were compared between groups. Cox proportional hazards regression was used to identify factors associated with mid-term MACE. Kaplan–Meier analysis was performed to evaluate differences in event-free survival, and receiver operating characteristic (ROC) curve analysis was used to assess the predictive performance of GLS.</p> Results <p>Mid-term MACE incidence was higher in the low-GLS group. Age, hyperlipidemia, history of coronary artery disease (CAD), low-density lipoprotein cholesterol (LDL-C), left ventricular end-systolic volume (LVESV), and GLS were significantly associated with the occurrence of mid-term MACE. History of CAD and LDL-C remained independent predictors of mid-term MACE, whereas GLS showed a borderline association after adjustment for LVEF and clinical covariates. Kaplan-Meier survival analysis demonstrated a significantly higher cumulative incidence of mid-term MACE in the low-GLS group. ROC curve analysis indicated that GLS had modest predictive value for mid-term MACE (area under the curve = 0.616).</p> Conclusion <p>GLS was associated with mid-term MACE and demonstrated incremental predictive value when combined with LVEF, and may provide complementary clinical value for early risk stratification.</p>