EP06* The subarachnoid hemorrhage early brain edema score (SEBES) as radiographic marker of clinically relevant intracranial hypertension and unfavorable outcome after subarachnoid hemorrhage

not related to aneurysm repair. Circulatory failure and severe intracranial hypertension prior to ECI, or within 3 days from bleeding if no ECI, were retrospectively determined. The association between ECI, prior circulatory failure, severe intracranial hypertension and patient outcomes was tested using uniand multivariate analyses. Results Seven-hundred-and-fifty-three patients with aSAH were included. ECI were observed in 40 patients with a prevalence of 5.3% (95% CI; 3.7–6.9%). New ECI lesions developed in-hospital in 70% of cases. Circulatory failure or severe intracranial hypertension was more common in patients with ECI compared to those without ECI (90% vs.11% respectively <0.001). In ECI patients, in-hospital occurrence of circulatory failure or severe intracranial hypertension was observed in 60% of cases, and was significantly associated new in-hospital ECI lesions (71%vs.33% in patients without new in-hospital ECI lesions, P=0.036). ECI was independently associated with WFNS grade (OR=2.3, CI95%=1.5–3.6, P<0.001), circulatory failure (OR=4.7, CI95%=1.8–11,P=0.001), severe intracranial hypertension (OR=11.1, CI95%=3.8–32.3, P<0.001), mortality at 1month (OR=6.3, CI95%=2.9–13.5, P<0.001), and poor outcome in survivors (modified Rankin score>3 at 6-month) (OR=3.8, CI95%=1.22–11.9, P=0.021). Conclusions ECI following aSAH is associated with prior brain haemodynamic impairment occurring mainly in-hospital, representing a potential therapeutic target in poor-grade aSAH.