Prehospital Prognostication after Out-of-Hospital Cardiac Arrest in Tertiary Care Centers: The R-EDByUS Score in the JAAM-OHCA Registry.

Aim

The R-EDByUS score predicts unfavorable neurological outcomes after out-of-hospital cardiac arrest (OHCA) using prehospital variables alone, with separate models based on return of spontaneous circulation (ROSC) status at hospital arrival. However, whether the score remains valid in patients transported to tertiary care centers is uncertain. We therefore aimed to validate it externally in this setting.

Methods

Using the JAAM-OHCA Registry, we analyzed adult patients with presumed cardiogenic OHCA transported to tertiary care centers. The regression-based R-EDByUS score was applied to predict unfavorable neurological outcome (Cerebral Performance Category 3-5) at 1 month in the prehospital ROSC and ongoing cardiopulmonary resuscitation (CPR) cohorts. Discrimination and calibration were assessed, and score performance was examined across in-hospital intervention subgroups (percutaneous coronary intervention, targeted temperature management, and extracorporeal membrane oxygenation). We also assessed the proportion of patients with unfavorable outcomes among those with a predicted probability ≥99%.

Results

Of 29,345 patients, 3,305 were classified into the prehospital ROSC cohort and 26,040 into the ongoing CPR cohort. The score showed good discrimination, with areas under the curve of 0.906 and 0.913, and good calibration in the prehospital ROSC cohort. Discrimination was lower among patients who received PCI, TTM, or ECMO in the ongoing CPR cohort. Among patients with a predicted probability ≥99%, 100% (112/112; prehospital ROSC) and 99.9% (20,560/20,588; ongoing CPR) had unfavorable outcomes.

Conclusion

The R-EDByUS score showed good discrimination in the JAAM-OHCA Registry, supporting its use for early risk stratification in cardiogenic OHCA even in tertiary care centers.