Abstract
Introduction Early differential diagnosis of acute cerebrovascular events remains a key clinical challenge, particularly during the hyperacute phase. This study aimed to assess plasma amino acid profiles and their dynamic changes as potential biomarkers and to evaluate their contribution to diagnostic accuracy. Methods This prospective observational clinical and laboratory study included 297 participants: 122 patients with acute ischemic stroke (AIS), 50 with hemorrhagic stroke (HS), 50 with transient ischemic attack (TIA), and 75 control participants. Plasma concentrations of six amino acids were determined using high-performance liquid chromatography coupled with mass spectrometry (HPLC-MS). Patients with acute cerebrovascular disease were sampled at 3-4.5 h and 12 h after symptom onset, whereas control participants provided a baseline sample only. Statistical analyses included non-parametric tests, correlation analysis, ROC curve analysis, and multivariable logistic regression. Results Significant between-group differences in amino acid concentrations were observed, particularly during the hyperacute phase. Individual amino acids showed limited discriminative ability when assessed in isolation (AUC approximately 0.61-0.65). Analysis of temporal changes identified additional subtype-related metabolic patterns, particularly in the differentiation of AIS and TIA. Addition of metabolomic variables to the clinical model increased the AUC from 0.734 to 0.803 (DeLong p = 0.007). Discussion Plasma amino acid profiles are associated with systemic metabolic alterations during acute cerebrovascular events. Although individual metabolites have limited diagnostic utility as standalone biomarkers, their integration with clinical variables and assessment of temporal changes may provide complementary information for early diagnostic differentiation.