ABSTRACT NUMBER: ESOC2026A1476 WAKE UP INTRACEREBRAL HEMORRHAGE: AN OBSERVATIONAL STUDY FROM THE SWEDISH STROKE REGISTRY

Abstract Background and aims Waking up with symptoms is not uncommon in intracerebral hemorrhage (ICH). Studies comparing wake-up ICH (WU-ICH) and known onset ICH have reported conflicting results regarding baseline differences and outcomes. We aimed to describe clinical characteristics, mortality, and functional outcomes in patients with wake-up ICH compared to known onset ICH in a large national registry study. Methods We included all patients diagnosed with ICH registered in the Swedish Stroke Registry (Riksstroke) during 2017-22 with either wake-up or known onset time. We compared characteristics, mortality, and functional outcomes at 3 months. Results Of 9769 patients, 2121 (22%) had WU-ICH and 7648 (78%) had known onset time. Median (IQR) last-known-well to hospital time was 5.4 h (2.1-10.8 h) vs 1.3 h (1.1-1.4 h). Patients with WU-ICH had higher rates of pre-ICH dependence, previous stroke, antithrombotic and antihypertensive treatment, and diabetes. WU-ICH had a higher unadjusted hazard ratio (HR) for death at 3 months, 1.14 (95% CI 1.05-1.24 p=0.002). Adjusted for differences in age, sex, pre-ICH dependence, antithrombotic treatment, previous stroke, and level of consciousness on admission, the aHR for death was 0.93 (95% CI 0.85-1.02, p = 0.11) compared to known onset ICH. Unadjusted shift analysis for worse functional outcome in WU-ICH vs known onset ICH had an odds ratio of 1.15 (95% CI 1.05 – 1.27). Adjusted for the same variables as for mortality, WU-ICH had aOR 0.75-0.79 (95% CI <1) in all possible dichotomizations. Conclusions Patients with WU-ICH had similar mortality and functional outcomes at 3 months after adjusting for higher disease burden prior ICH. Conflict of interest All authors: Nothing to disclose. Figure 1 - belongs to Conclusions