Using eosinophil response to predict cardiovascular outcomes in patients with ST- elevation myocardial infarction who undergo primary percutaneous coronary intervention

Eosinophils have been implicated in mediating the inflammatory response after ST-elevation myocardial infarction (STEMI), but its role as a biomarker predicting major adverse cardiovascular events (MACE) remains unclear. We aimed to evaluate the predictive value of eosinophil response on 30-day and 1-year MACE post primary percutaneous coronary intervention (PCI) after STEMI. Single centre retrospective cohort study of STEMI patients undergoing PCI. Eosinophil response was defined as the change in peripherally circulating eosinophils cell count at admission minus 48 hours post primary PCI. Primary endpoints were 30-day and 1-year MACE. Receiver operating characteristic (ROC) curves were created to identify optimal cut-off predicting MACE. Multivariate logistic regression analyses were used to determine if the ROC cut-off was an independent predictor of MACE. Of the 366 patients in this study (median age 61 years [53.0-71.0]; 267 males [73%]), 41 patients (11.2%) and 78 patients (21.3%) developed MACE at 30-days and 1-year. The optimal ROC curve cut-off predicting MACE was an eosinophil response of greater than -0.05x10ˆ9/L (ΔEos>-0.05). It had a sensitivity, specificity, and positive and negative predictive value of 83, 39, 6 and 98% for 30-day MACE, and 74, 39, 19 and 88% for 1-year MACE. An ΔEos>-0.05 change was associated with a threefold higher likelihood of MACE at 30-days ( OR 3.1 , 95% CI 1.04-9.07 , p= 0.042), but not 1-year. An eosinophil response of -0.05x10ˆ9L at 48 hours following primary PCI post STEMI is highly sensitive at predicting 30-day MACE, and in its absence, holds a high negative predictive value. KEY HIGHLIGHTS • What is already known about this topic • A decrease in peripherally circulating eosinophils post STEMI is predictive of higher in-hospital mortality and morbidity. However, the role of eosinophil response on longer term adverse cardiovascular outcomes remains unknown. • What this study adds • This study evaluates whether eosinophil response post primary PCI for STEMI has any predictive value on 30-day and 1-year MACE and mortality. • How this study might affect clinical practice • The results of this study may provide clinician a simple and useful biomarker to help risk stratify patients and evaluate treatment response post primary PCI following a STEMI.