Background: The correlation between glial fibrillary acidic protein (GFAP) and symptomatic intracranial hemorrhage (sICH) in acute ischemic stroke (AIS) patients undergoing endovascular thrombectomy (EVT) treatment remains uncertain. We aimed to assess the association between levels of GFAP in the bloodstream and the occurrence of sICH.
Methods: Between June 2019 and May 2023, 142 consecutive AIS patients undergoing EVT at Stroke Center and 35 controls from the Physical Examination Center were retrospectively included. The levels of GFAP in the bloodstream were quantified using enzyme-linked immunosorbent assay prior to endovascular treatment (T1) and 24 h after the procedure (T2). The identification of sICH was based on the Heidelberg Bleeding Classification.
Results: Serum GFAP levels at T1 in AIS patients were significantly higher than those in the controls (0.249 [0.150– 0.576] versus 0.065 [0.041– 0.110] ng/mL, p = 0.001), and there was a notably elevation in GFAP levels at T2 compared to T1 (3.813 [1.474, 5.876] versus 0.249 [0.150– 0.576] ng/mL, p = 0.001). Of the 142 AIS patients, 18 (14.5%) had sICH after EVT. Serum GFAP levels at T2 showed significant associations with sICH in both the unadjusted model (OR 1.513, 95% CI 1.269– 1.805, p = 0.001) and multivariable adjusted model (OR 1.518, 95% CI 1.153– 2.000, p = 0.003). Furthermore, the addition of GFAP at T2 to conventional model resulted in a significant enhancement of risk reclassification for sICH (integrated discrimination improvement [IDI] 0.183, 95% CI 0.070– 0.295, p = 0.001).
Conclusion: Serum GFAP levels were notably increased in AIS patients 24 h after EVT. Elevated GFAP levels were correlated to an elevated risk of sICH. GFAP could potentially serve as a dependable indicator for sICH in AIS individuals who treated with EVT.

Keywords: glial fibrillary acidic protein, stroke, symptomatic intracranial hemorrhage, indicator, endovascular thrombectomy