Performance of GFAP and UCH-L1 for Early Acute Stroke Diagnosis in the Emergency Department

<b>Background</b>: Rapid identification and treatment of stroke are essential for the patient. Our objective was to determine the diagnostic utility of glial fibrillary acidic protein (GFAP) and ubiquitin C-terminal hydrolase L1 (UCH-L1) in the emergency department to identify and differentiate acute stroke within 4.5 h of symptom onset in patients admitted with a stroke code alert. <b>Methods:</b> This study included 85 patients with a "code stroke alert" upon arrival at the emergency department. Individuals were grouped in two categories: patients with stroke (including 69 patients) and patients without stroke (including 16 patients). The research was conducted at the Emergency Municipal Clinical Hospital in Timișoara, Romania, the county's second-largest hospital, which lacks a neurologist and a dedicated stroke unit. <b>Results:</b> No significant differences were observed between the two groups (with stroke and without stroke) regarding most demographic or admission parameters. Significant differences were observed for the biomarkers GFAP (142.91 ± 102.19 pg/mL in patients with acute stroke vs. 37.76 ± 19.92 pg/mL in patients without stroke (<i>p</i> < 0.001)) and UCH-L1 (1307.68 ± 967.54 pg/mL in stroke patients vs. 189.81 ± 92.69 pg/mL in patients without stroke (<i>p</i> < 0.001)). Within the stroke group, 37 patients had acute ischemic stroke, while 32 patients were diagnosed with hemorrhagic stroke based on brain CT imaging. GFAP achieved an accuracy of 94.2% for differentiating hemorrhagic from ischemic stroke, with a cut-off value of 77.15 pg/mL. <b>Conclusions:</b> GFAP excellently differentiated acute stroke from stroke mimics, with high sensitivity, perfect specificity, and strong predictive values. Integrating GFAP and UCH-L1 measurements into emergency protocols may enhance stroke diagnosis, optimize patient triage, and ultimately improve outcomes by facilitating the faster initiation of appropriate therapies.