Internal environment disorders independently predict out-of-hospital cardiac arrest in acute myocardial infarction
Y Zhu, J Yang, X Gao, Y Wu, Y YangAbstract
Objective
To determine whether internal environment disorders independently predict out-of-hospital cardiac arrest (OHCA) risk in acute myocardial infarction (AMI) and develop a novel score quantifying their aggregate burden.
Methods
This study based on China Acute Myocardial Infarction (CAMI) Registry (2013–2014; n=24,223 AMI patients). OHCA was defined as pre-hospital cardiac arrest. The Internal Environment Disorder (IED) score (0–4 points) integrated admission: hypokalemia (serum potassium <3.5 mmol/L), hyperglycemia (serum glucose ≥7.8 mmol/L), hyperleukocytosis (white blood cell count ≥10×10⁹/L), and kidney dysfunction (estimated glomerular filtration rate [eGFR] <90 mL/min/1.73m²; 1 point each). Primary analysis: 599 OHCA patients vs. 2,995 matched controls (1:5; age/sex/ST-elevation). Secondary cohort: 961 in-hospital cardiac arrest (IHCA) patients vs. 4,805 controls—using admission markers before arrest to exclude reverse causality. Multivariable regression adjusted for established predictors.
Results
OHCA patients had significantly higher prevalence of all IED components (hypokalemia 27.6% vs. 14.8%; hyperglycemia 58.2% vs. 36.6%; hyperleukocytosis 67.5% vs. 46.8%; kidney dysfunction 55.5% vs. 41.8%; all p<0.001) and severe IED scores (score 3–4: 39.0% vs. 13.2%). A graded association existed between IED score and OHCA risk: aORs vs. score 0 were 1.62 (1.11–2.36) for score 1, 3.02 (2.10–4.34) for score 2, 7.60 (5.20–11.10) for score 3, and 9.57 (5.55–16.48) for score 4. Higher admission IED scores also predicted IHCA risk (p<0.001).
Conclusion
The novel IED score integrates simple, universally available admission markers into a powerful tool for early identification of AMI patients at high risk of OHCA , facilitating timely, life-saving interventions.Central Illustration