MIRACLE2 Score Compared With Downtime and Current Selection Criterion for Invasive Cardiovascular Therapies After OHCA

Abstract

Background: The MIRACLE₂ score is the only risk score that does not incorporate and can be used for selection of therapies after out-of-hospital cardiac arrest (OHCA).

Objectives: This study sought to compare the discrimination performance of the MIRACLE₂ score, downtime, and current randomized controlled trial (RCT) recruitment criteria in predicting poor neurologic outcome after out-of-hospital cardiac arrest (OHCA).

Methods: We used the EUCAR (European Cardiac Arrest Registry), a retrospective cohort from 6 centers (May 2012-September 2022). The primary outcome was poor neurologic outcome on hospital discharge (cerebral performance category 3-5).

Results: A total of 1,259 patients (total downtime = 25 minutes; IQR: 15-36 minutes) were included in the study. Poor outcome occurred in 41.8% with downtime <30 minutes and in 79.3% for those with downtime >30 minutes. In a multivariable logistic regression analysis, MIRACLE₂ had a stronger association with outcome (OR: 2.23; 95% CI: 1.98-2.51; P < 0.0001) than zero flow (OR: 1.07; 95% CI: 1.01-1.13; P = 0.013), low flow (OR: 1.04; 95% CI: 0.99-1.09; P = 0.054), and total downtime (OR: 0.99; 95% CI: 0.95-1.03; P = 0.52). MIRACLE₂ had substantially superior discrimination for the primary endpoint (AUC: 0.877; 95% CI: 0.854-0.897) than zero flow (AUC: 0.610; 95% CI: 0.577-0.642), low flow (AUC: 0.725; 95% CI: 0.695-0.754), and total downtime (AUC: 0.732; 95% CI: 0.701-0.760). For those modeled for exclusion from study recruitment, the positive predictive value of MIRACLE₂ ≥5 for poor outcome was significantly higher (0.92) than the CULPRIT-SHOCK (Culprit lesion only PCI Versus Multivessel PCI in Cardiogenic Shock) (0.80), EUROSHOCK (Testing the value of Novel Strategy and Its Cost Efficacy In Order to Improve the Poor Outcomes in Cardiogenic Shock) (0.74) and ECLS-SHOCK (Extra-corporeal life support in Cardiogenic shock) criteria (0.81) (P < 0.001).

Conclusions: The MIRACLE₂ score has superior prediction of outcome after OHCA than downtime and higher discrimination of poor outcome than the current RCT recruitment criteria. The potential for the MIRACLE₂ score to improve the selection of OHCA patients should be evaluated formally in future RCTs.

Keywords: out-of-hospital cardiac arrest; resuscitation; risk scores.