Comparison of MIRACLE2 and NULL-PLEASE scores for predicting survival and neurological outcomes following out-of-hospital cardiac arrest

Aims

Early prognostication following out-of-hospital cardiac arrest (OOHCA) remains challenging. The MIRACLE2 and NULL-PLEASE scores have been developed to aid early outcome prediction; however, direct comparative data between the two are limited. This study aimed to evaluate and compare both scoring systems in predicting survival and neurological outcome after OOHCA.

Methods

This retrospective single-centre analysis included 39 consecutive patients who achieved return of spontaneous circulation following OOHCA. Demographic, clinical, and outcome data were extracted from electronic health records. For each patient, MIRACLE2 and NULL-PLEASE scores were calculated. The primary outcome was survival to hospital discharge; the secondary outcome was favourable neurological recovery, defined as a Cerebral Performance Category (CPC) ≤ 2. Predictive performance was assessed using receiver operating characteristic (ROC) analysis (area under the curve, AUC) and Mann–Whitney testing.

Results

A total of 39 patients were included; 26 (67%) survived to discharge, and 24 (63%) achieved favourable neurological outcomes. The MIRACLE2 score demonstrated poor predictive ability for both survival (AUC = 0.56, 95% CI 0.35–0.77, p = 0.60) and favourable neurological recovery (AUC = 0.52, 95% CI 0.33–0.72, p = 0.81). In contrast, the NULL-PLEASE score showed good discrimination for survival (AUC = 0.74, 95% CI 0.56–0.92, p = 0.01) and significant discrimination for poor neurological outcome (AUC = 0.27, 95% CI 0.10 0.44, p = 0.009; equivalent to 0.73 when oriented toward adverse prognosis). Overall, higher NULL-PLEASE scores were associated with mortality and poor neurological recovery, whereas MIRACLE2 failed to meaningfully discriminate outcomes.

Conclusion

Within this single-centre cohort, the NULL-PLEASE score outperformed MIRACLE2 in predicting both survival and neurological recovery following OOHCA.Higher NULL-PLEASE scores were strongly associated with mortality and poor neurological outcomes. These findings suggest the NULL-PLEASE score may provide superior early risk stratification and could aid decision-making in post-resuscitation care. Further validation in larger multicentre studies is warranted.

Dr Yumna Usmani is a foundation year two doctor who has worked at Sandwell and West Birmingham Hospitals and University hospitals Birmingham UK, rotating through medical and surgical specialties. She graduated from University of Leicester in 2024.