ABSTRACT NUMBER: ESOC2026LB59 PRE-ICH ANTI-PLATELET MEDICATION SELECTS PATIENTS AT HIGH RISK FOR HEMATOMA EXPANSION THAT IS DECREASED BY RECOMBINANT FACTOR VIIA

Abstract Background and aims Hematoma expansion (HE) is a preventable cause of poor outcome in patients with acute intracerebral hemorrhage (ICH). Predicting which patients will have HE is crucial to target hemostatic treatment. Patients who take pre-ICH anti-platelet medication may be at higher risk for HE, however, it is unclear if hemostatic treatment would be more effective in these patients. Methods We identified patients who took pre-ICH anti-platelet medications at enrollment into FASTEST, a prospective, randomized trial of recombinant Factor VII (rFVIIa) within two hours of symptom onset. HE was measured centrally from serial CT scans. These data are from a pre-planned interim analysis. Results We enrolled 626 patients. Anti-platelet medications prior to enrollment were none (N=541, 86%), aspirin only (N=66, 11%), P2Y12 inhibitors (e.g., clopidogrel, N=16, 3%), and both aspirin and P2Y12 inhibitors (N=3, <1%). Baseline severity of ICH and time to imaging were similar between groups. Randomization to rFVIIa was predictive of less HE overall, especially in patients with pre-ICH aspirin use. In patients with no pre-ICH antiplatelet use, rFVIIa reduced hematoma expansion from 4.7 +/- 12.8 mL to 1.5 +/- 5.6 mL (P=0.002), a difference of 3.2 mL (P=0.0002). In patients with pre-ICH aspirin use, rFVIIa decreased HE from 12.3 +/- 19.3 mL to 1.4 +/- 2.8 mL, a difference of 10.9 mL (P=0.004). Conclusions Pre-ICH aspirin and short time from symptom onset identifies patients at high risk for HE, a targetable population for haemostatic treatment. Patients who took pre-ICH aspirin had substantial HE that was attenuated by rFVIIa. Conflict of interest Table 1 - belongs to Results