Abstract Body: Introduction: Brain injury is the main cause of death and disability post-cardiac arrest, and hypoxic-ischemic brain injury (HIBI) severity is associated with poor outcomes. There is limited information about the co-occurrence of acute ischemic stroke with HIBI post-cardiac arrest and its impact on outcome.
Methods: We performed a retrospective analysis of brain MRI reports from patients with cardiac arrest in a multicenter cohort to evaluate the incidence of acute ischemic stroke and HIBI. Patients with MRI in the first 7 days after cardiac arrest were included. Patients with traumatic brain injury, intracranial hemorrhage, recent neurosurgical procedures, or ischemic stroke at admission were excluded. A secondary manual review by a board-certified vascular neurologist was pursued if the MRI report did not specify the absence of ischemic stroke. Univariate and multivariable analysis was performed to explore the characteristics of the ischemic lesions and to evaluate if it was related to poor functional outcomes (i.e., Cerebral Performance Category of 4-5).
Results: Among 396 patients who met the inclusion criteria, 91 had cerebral infarction based on MRI (22.9%). The most common pattern of stroke was multifocal small embolic (51.6%), followed by single embolic (25.3%), watershed (12.1%), territorial (7%), and lacunar (5%). The patients with acute ischemic stroke were older (p<0.01). In the logistic regression, older age, non-witnessed cardiac arrest, and non-shockable rhythm were associated with worse prognosis (p<0.05). The presence of acute ischemic stroke was not significantly associated with the cause of arrest, percutaneous coronary intervention (PCI), or the use of targeted temperature management (TTM). Individuals with acute ischemic stroke had lower rates of HIBI (odds ratio [OR] 0,55 [0.34-0.87], p<0.01). In univariate and multivariate analysis, the presence of acute ischemic stroke was not associated with outcome, as opposed to the presence of HIBI (p<0.01).
Conclusion: More than one-fifth of the comatose patients after cardiac arrest present acute ischemic stroke on MRI. The most common pattern is multifocal embolic, which may be related to cardiac embolism and hypercoagulable state after the arrest and not from PCI or cardiac arrest rhythm. The detection of acute ischemic stroke is higher among individuals without HIBI and is not associated with worse outcomes.