A Practical Risk-Score for Early Prediction of Neurological Outcome after Out-of-Hospital Cardiac Arrest –MIRA2CLE2

Aims The purpose of this study was to develop a practical risk−score to predict poor neurological outcome after out−of−hospital cardiac arrest (OOHCA) for use on arrival to a Heart Attack Centre. Methods and Results Between May 2012 and December 2017, 1055 patients had OOHCA in our region, of whom 373 patients were included in the King's Out of Hospital Cardiac Arrest Registry (KOCAR). We performed prediction modelling with multi-variable logistic regression to identify factors independently predictive of the primary outcome in order to derive a risk score. This was externally validated in two independent cohorts comprising 474 patients. The primary outcome was poor neurological function at 6−month follow−up (Cerebral Performance Category 3-−). Seven independent variables for prediction of outcome were identified: Missed (Unwitnessed) arrest, Initial non-shockable rhythm, non-Reactivity of pupils, Age, Changing intra-arrest rhythms, Low pH<;7.20 and Epinephrine administration. From these variables, the MIRA2CLE2 score was developed which had an AUC of 0.90 in the development and 0.85 and 0.89 in the validation cohorts. 3 risk groups of the MIRA2CLE2 were defined − Low risk (≤2−5.6% risk of poor outcome; Intermediate risk (3−4−55.4% of poor outcome) and high risk (≥5−92.3% risk of poor outcome). The risk-score performance was equivalent in a sub-group of patients referred for early angiography and revascularisation where appropriate. Conclusions The MIRA2CLE2 score is a practical risk score for early accurate prediction of poor neurological outcome after OOHCA, which has been developed for simplicity of use on admission to a Heart Attack Centre.