Acute brain injury (ABI) can cause out of hospital cardiac arrest (OHCA). The aim of this study was to compare clinical features, mortality and potential for organ donation in patients with OHCA due to ABI vs other causes.

From January 2017 to December 2018, all adult patients presenting to ED for OHCA were considered for the study. Two physicians established the definitive cause of OHCA, according to clinical, laboratory, diagnostic imaging and autoptic findings. Clinical features in patients with OHCA due to ABI or other causes were compared.

280 patients were included in the analysis. ABI was the third most frequent cause of OHCA (21, 7.5%); ABIs were 8 subarachnoid hemorrhage, 8 intracerebral hemorrhage, 2 ischemic stroke, 2 traumatic spinal cord injury and 1 status epilepticus respectively. Neurological prodromes such as seizure, headache and focal neurological signs were significantly more frequent in patients with OHCA due to ABI (OR 5.34, p = 0.03; OR 12.90, p = 0.02; and OR 66.53, p < 0.01 respectively) while among non-neurological prodromes chest pain and dyspnea were significantly more frequent in patients with OHCA due to other causes (OR 14.5, p < 0.01; and OR 10.4, p = 0.02 respectively). Anisocoria was present in 19% of patients with OHCA due to ABI vs 2.7% due to other causes (OR 8.47, p < 0.01). In 90.5% of patients with ABI and in 53.1% of patients with other causes the first cardiac rhythm was non shockable (OR 8.1; p = 0.05). Multivariate logistic regression analysis revealed that older age, active smoking, post-traumatic OHCA, neurological prodromes, anisocoria at pupillary examination were independently associated with OHCA due to ABI. Patients with ABI showed a higher mortality compared with the other causes group (19 pts., 90.5% versus 167 pts., 64.5%; p = 0.015). Potential organ donors were more frequent among ABI than other causes group (10 pts., 47.6% vs 75 pts., 28.9%) however the difference did not reach the statistical significance (p = 0.07).

ABI is the third cause of OHCA. Neurological prodromes, absence of chest pain and dyspnea before cardiac arrest, anisocoria and initial non-shockable rhythm might suggest a neurological etiology of the cardiac arrest. Patients with OHCA due to ABI has an unfavorable outcome, however, they could be candidate to organ donation.