ABSTRACT NUMBER: ESOC2026A2087 THE PLASMA GFAP RELEASE RATE AS A BIOMARKER OF RAPID INTRACEREBRAL HEMATOMA EXPANSION

Abstract Background and aims Intracerebral hemorrhage (ICH) patients with rapid early hematoma expansion may potentially benefit the most from immediate therapeutic interventions, including hemostatic treatments, blood pressure lowering, and early minimally invasive surgery. We explored the plasma GFAP release rate as a biomarker of hematoma expansion. Methods Laboratory measurement of GFAP was performed with Alphalisa® in consecutive plasma samples collected in the prehospital setting and upon hospital arrival, and the GFAP release rate was calculated between the samples (pg/mL/min). Results We included 107 ICH patients with a median (IQR) last-known-well to sampling time of 50 (40-80) minutes for prehospital and 94 (69-120) minutes for admission samples, and the time between samples was 32 (25-45) minutes. The GFAP release rate correlated strongly with hematoma volume (Spearman’s ρ=0.48, p<0.001), and the imaging based early bleeding rate (Spearman’s ρ=0.43, p<0.001, bleeding rate defined as computed tomography (CT) ICH volume / LKW-to-CT-time). A diagnostic rule (prehospital GFAP >8000 pg/mL or GFAP release rate >10 pg/mL/min) identified an early bleeding rate of >5mL/h with 70.8% sensitivity and 83.3% specificity (PPV 86.8%, NPV 64.8%). A second diagnostic rule (prehospital GFAP >10000 pg/mL or GFAP release rate >100 pg/mL/min) identified an early bleeding rate of >10mL/h with 63.6% sensitivity and 92.1% specificity (PPV 84.8%, NPV 78.4%). Conclusions The GFAP release rate may have future value as an adjunct point-of-care method to estimate the speed of hematoma expansion in both the prehospital and early follow-up phases of ICH, to help select patients for therapeutic interventions. Conflict of interest All authors: nothing to disclose