Alzheimer Disease Blood Biomarkers in Patients With Out-of-Hospital Cardiac Arrest

Key Points Question Are Alzheimer disease blood biomarkers altered in patients with hypoxic-ischemic injury after cardiac arrest? Findings In this case-control study, blood phosphorylated tau (p-tau) levels were significantly elevated 24 hours after cardiac arrest and were associated with poorer neurologic outcome. Unlike neurofilament light (NfL) and total tau (t-tau), p-tau levels decreased after 24 hours and were no longer associated with neurological outcome; amyloid-β (Aβ) peptides demonstrated moderate increases and were only weakly associated with neurological outcome. Meaning These findings of the increase and dynamics of p-tau in blood following cardiac arrest, which differ from those of t-tau and NfL, suggest alternative mechanisms of p-tau origin and release from the increases observed due to Aβ deposition and neuronal tau phosphorylation in Alzheimer disease.