Objective:To investigate associations between cardiac biomarkers with stroke severity and short-term outcome in patients with acute ischemic stroke (AIS).Methods:Patients with AIS admitted to the Affiliated Hospital of Qingdao University from June 2018 to February 2024 whose etiological classification was large artery atherosclerosis (LAA), small vessel occlusion (SVO) or cardioembolism (CE) were included retrospectively. According to the National Institutes of Health Stroke Scale score at admission, patients were divided into mild stroke group (≤8) and moderate to severe stroke group (>8). According to the modified Rankin Scale score at discharge, patients were divided into good outcome group (≤2) and poor outcome group (>2). Multivariate logistic regression analysis was used to determine the independent correlation between cardiac biomarkers and short-term outcome. The predictive value of cardiac biomarkers for poor outcome in patients with AIS and different stroke etiology subtypes were evaluated using receiver operating characteristic (ROC) curves. Results:A total of 2 151 patients with AIS were enrolled, including 1 256 males (58.4%), aged 67.40±11.34 years. 1 079 patents were LAA type (50.2%), 679 were SVO type (31.6%), and 393 were CE type (18.3%); 1 223 were mild stroke (56.86%) and 928 (43.14%) were moderate to severe stroke; 1 357 patients (63.09%) had good short-term outcome, and 794 (36.91%) had poor short-term outcome. Multivariate logistic regression analysis showed that N-terminal pro-B type natriuretic peptide (NT-proBNP), NT-proBNP/creatine kinase (CK) isoenzyme MB (CK-MB) ratio, and CK-MB/CK ratio were independent risk factors for poor short-term outcome. ROC curve analysis shows that the CK-MB/CK ratio had a higher predictive value for short-term poor outcome in patients with AIS (the area under the curve, 0.859, 95% confidence interval 0.839-0.879). Various cardiac biomarkers had a higher predictive value for short-term outcome of CE type and LAA type, but the predictive value for short-term outcome of SVO type was lower. Conclusions:Cardiac biomarkers are associated with the severity and poor outcome of AIS. NT-proBNP/CK-MB and CK-MB/CK ratios have higher predictive value for short-term poor outcome of AIS, especially in patients with CE type.