Early cerebral fluorodeoxyglucose positron emission tomography of the cerebral striatum predict survival in comatose out-of-hospital cardiac arrest patients

Aim Early prognostication is challenging in comatose patients after out-of-hospital cardiac arrest (OHCA) and return of spontaneous circulation (ROSC). Patients who regain Patients who regain consciousness within the first days after admission often have favorable cerebral outcomes. The striatum of the basal ganglia is known to influence consciousness, and cerebral fluorodeoxyglucose positron emission tomography (FDG PET) provides unique metabolic insights, though its prognostic value in OHCA is uncertain. Using FDG PET, we therefore investigated whether preserved cerebral metabolism in the cerebral striatum could predict survival in comatose patients following OHCA. Methods This single-center prospective cohort study included patients with ROSC after OHCA admitted between March 2022 and January 2025. FDG PET was performed within 48 hours from arrival while patients were still comatose. The primary outcome was difference in early FDG uptake in the cerebral striatum during coma, expressed as the Standardized Uptake Value ratio (SUVr) normalized to cerebellum, between patients who survived, and those who died. Secondary outcome was global difference in FDG uptake in the cerebral cortex. Group comparisons were performed using two-sided t-tests. Multivariable analyses were performed using logistic regression, adjusting for age, sex and time to ROSC. The predictive ability of cerebral FDG uptake was assessed using area under the receiver operating characteristics (AUCROC) curves. Results We included 34 patients, 27 men (79%) and 7 women (21%). Twenty patients (59%) survived. Age did not differ significantly between survivors and non-survivors (mean age: 66 years [SD ±9] versus 72 [SD ±9] respectively, P=0.08). In the cerebral striatum, SUVr was significantly higher in patients who survived compared with those who died (1.10 [SD ±0.08] versus 1.03 [SD ±0.08], P=0.015), (Figure 1). In the cerebral cortex, SUVr was 0.97 [SD ±0.04] in survivors versus 0.95 [SD ±0.08] in non-survivors, (P=0.25). In a logistic regression model, we found a significant association between striatum SUVr and survival (OR per 0.1-unit increase 3.26 [95% CI 1.18-8.98], P=0.022), and this association remained significant after multivariable adjustment (OR per 0.1-unit increase 4.31 [95% CI 1.38-21.86], P=0.031). The AUCROC value for survival was 0.75 [95% CI 0.569-0.931], (Figure 2). Conclusions In comatose patients with ROSC after OHCA, FDG uptake in the cerebral striatum was significantly higher in those who survived compared with those who died. Results were independent of age, sex and time to ROSC. This is the first study using FDG PET in OHCA patients showing a significant association between cerebral metabolism and survival.