Late neurologic and functional outcomes in patients with severe anoxic brain injury after cardiopulmonary arrest: a multicenter cohort study.

Background: Neurological prognostication after cardiac arrest remains challenging, and most patients with severe anoxic brain injury have an indeterminate prognosis despite multimodal assessment. Although delayed awakening has been reported in the era of targeted temperature management, long-term functional outcomes in this population remain poorly described. Methods: We conducted a retrospective multicenter cohort study across 18 hospitals to assess the late neurologic and functional outcomes of patients with severe anoxic-ischemic brain injury after cardiopulmonary arrest. Patients who were hospitalized between Jan 1, 2018 and Jan 1, 2023 with anoxic brain injury due to cardiopulmonary arrest were included if they were functionally independent at baseline (CPC 1-2) but remained comatose or in an unresponsive wakefulness syndrome (UWS)/vegetative state at 2 weeks. To study the natural course of disease, we included only patients whose families wanted to continue life-sustaining treatment at the time of inclusion, and those who survived at least three weeks after arrest. Neurological and functional outcomes were assessed longitudinally for up to 12 months using the Cerebral Performance Category (CPC) scale. Results: A total of 169 patients met inclusion criteria (mean age 52.9 years). Initial hospitalization was prolonged (mean length of stay 61.2 days). Twenty-seven patients died before hospital discharge. Of the 142 patients discharged, an additional 40 died within 12 months, for a total of 67 deaths (39.6%). Forty-four of these deaths were due to eventual withdrawal of life support, due to deteriorating medical status with superimposed medical complications. Among the 102 patients alive at 12 months, 99 remained severely disabled (CPC 3-4). Only three patients (1.8% of the cohort) regained CPC 1-2 at 12 months. Conclusions: In this large multicenter cohort of patients with severe anoxic brain injury who remained comatose or in a UWS/vegetative state at two weeks, functional recovery with CPC 1-2 at 12 months was rare. Although delayed neurological improvement may occur, favorable functional recovery was rare and prolonged aggressive care was most often associated with death or severe long-term disability. These findings provide additional outcome data to inform neuroprognostication and goals-of-care discussions after cardiac arrest.