Abstract 4146327: MIRACLE2 Score Effectively Stratifies Short-term Prognosis in Patients with Out-of-Hospital Cardiac Arrest Due to Acute Coronary Syndrome

Background: Despite advances in treatment strategies for out-of-hospital cardiac arrest (OHCA), prognosis remains poor. The MIRACLE2 score is an established risk stratification tool for cardiogenic OHCA, but its utility in acute coronary syndrome (ACS), a leading OHCA etiology, is unclear. Aims: To validate the prognostic performance of the MIRACLE2 score in OHCA patients with ACS undergoing urgent/emergent percutaneous coronary intervention (PCI). Methods: We conducted a single-center, observational study (COEDO-CPA registry) of consecutive cardiogenic OHCA patients from 2018-2024. Patients with OHCA due to ACS who underwent urgent/emergent PCI were stratified into high-risk (MIRACLE2 score >5), medium-risk (3-4), and low-risk (0-2) groups based on their MIRACLE2 scores. The primary endpoint was 30-day all-cause mortality, compared among risk groups using Kaplan-Meier analysis. Results: Of 124 cardiogenic OHCA patients, 80 with ACS-related OHCA undergoing PCI were analyzed (mean age 64.7 years, 89% male). The mean MIRACLE2 score was 3.2, with 18 high-risk, 30 medium-risk, and 32 low-risk patients. Mechanical circulatory support was used in 58%. The high-risk group tended to be older with higher lactate levels, worse renal function, elevated D-dimer, and longer cardiopulmonary resuscitation duration compared to lower-risk groups. Kaplan-Meier analysis demonstrated a graded increase in 30-day mortality across risk groups, with effective risk stratification by the MIRACLE2 score (log-rank p=0.003). Conclusion: Among OHCA patients with ACS undergoing PCI, the MIRACLE2 score effectively stratified short-term mortality risk. This validated risk stratification tool could guide treatment strategies and resource allocation in this critically ill population. Incorporating the MIRACLE2 score into OHCA management pathways may optimize care for ACS-related OHCA.