Eosinophil percentage as a new prognostic marker in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention

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

Objective

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.

Methods

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 h 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.

Results

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 -0.05 × 10^9/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.

Conclusion

An eosinophil response of -0.05 × 10^9L at 48 h following primary PCI post STEMI is highly sensitive at predicting 30-day MACE, and in its absence, holds a high negative predictive value.

Differential roles of eosinophils in cardiovascular disease

Eosinophils are essential innate immune cells in allergic responses. Accumulating evidence indicates that eosinophils also participate in the pathogenesis of cardiovascular diseases (CVDs). In clinical studies, high blood eosinophil counts and eosinophil cationic protein levels have been associated with an increased risk of CVD, including myocardial infarction (MI), cardiac hypertrophy, atrial fibrillation, abdominal aortic aneurysm (AAA) and atherosclerosis. However, low blood eosinophil counts have also been reported to be a risk factor for MI, heart failure, aortic dissection, AAA, deep vein thrombosis, pulmonary embolism and ischaemic stroke. Although these conflicting clinical observations remain unexplained, CVD status, timing of eosinophil data collection, and tissue eosinophil phenotypic and functional heterogeneities might account for these discrepancies. Preclinical studies suggest that eosinophils have protective actions in MI, cardiac hypertrophy, heart failure and AAA. By contrast, cationic proteins and platelet-activating factor from eosinophils have been shown to promote vascular smooth muscle cell proliferation, vascular calcification, thrombomodulin inactivation and platelet activation and aggregation, thereby exacerbating atherosclerosis, atrial fibrillation, thrombosis and associated complications. Therefore, eosinophils seem to promote calcification and thrombosis in chronic CVD but are protective in acute cardiovascular settings. In this Review, we summarize the available clinical and preclinical data on the different roles of eosinophils in CVD.

Eosinophil percentage and platelet counts: Association with in-hospital mortality in ST-segment elevated myocardial infarction

BACKGROUND

ST-segment elevation myocardial infarction (STEMI) results from coronary artery blockage due to ruptured atherosclerotic plaque. Eosinophils play a dual role in STEMI, contributing to thrombus formation and tissue repair. This study investigates the association between eosinophil percentage, platelet counts, and in-hospital prognosis in STEMI patients.

METHODS

A cross-sectional study was conducted from September 2019 to February 2020, including patients aged 18 and above with a STEMI diagnosis. In-hospital mortality, arrhythmia, and left ventricular ejection fraction (LVEF) were recorded. Demographic data, clinical manifestations, and laboratory investigations were collected. Data were analyzed using SPSS (version 25.0), with a P value of <0.05 considered significant.

RESULTS

The study included 100 STEMI patients with a mean age of 65±13.26 years; 75% were male. The mortality rate was 13%. A significant relationship was found between eosinophil percentage and mortality (p=0.032), and platelet count also correlated significantly with mortality (p=0.008). The association between eosinophil percentage and EF was significant (p<0.001). The area under the ROC curve was 0.705 (95% CI 0.605 - 0.792) for platelet counts and 0.679 (95% CI 0.577 - 0.770) for eosinophil percentage in differentiating live and expired patients.

CONCLUSION

Platelet count could be a significant prognostic indicator for in-hospital outcomes in STEMI patients, suggesting an increased risk of mortality. Additionally, there is a notable relationship between eosinophil percentage and ejection fraction (EF).

Cationic proteins from eosinophils bind bone morphogenetic protein receptors promoting vascular calcification and atherogenesis

AIMS

Blood eosinophil count and eosinophil cationic protein (ECP) concentration are risk factors of cardiovascular diseases. This study tested whether and how eosinophils and ECP contribute to vascular calcification and atherogenesis.

METHODS AND RESULTS

Immunostaining revealed eosinophil accumulation in human and mouse atherosclerotic lesions. Eosinophil deficiency in ΔdblGATA mice slowed atherogenesis with increased lesion smooth muscle cell (SMC) content and reduced calcification. This protection in ΔdblGATA mice was muted when mice received donor eosinophils from wild-type (WT), Il4-/-, and Il13-/- mice or mouse eosinophil-associated-ribonuclease-1 (mEar1), a murine homologue of ECP. Eosinophils or mEar1 but not interleukin (IL) 4 or IL13 increased the calcification of SMC from WT mice but not those from Runt-related transcription factor-2 (Runx2) knockout mice. Immunoblot analyses showed that eosinophils and mEar1 activated Smad-1/5/8 but did not affect Smad-2/3 activation or expression of bone morphogenetic protein receptors (BMPR-1A/1B/2) or transforming growth factor (TGF)-β receptors (TGFBR1/2) in SMC from WT and Runx2 knockout mice. Immunoprecipitation showed that mEar1 formed immune complexes with BMPR-1A/1B but not TGFBR1/2. Immunofluorescence double-staining, ligand binding, and Scatchard plot analysis demonstrated that mEar1 bound to BMPR-1A and BMPR-1B with similar affinity. Likewise, human ECP and eosinophil-derived neurotoxin (EDN) also bound to BMPR-1A/1B on human vascular SMC and promoted SMC osteogenic differentiation. In a cohort of 5864 men from the Danish Cardiovascular Screening trial and its subpopulation of 394 participants, blood eosinophil counts and ECP levels correlated with the calcification scores of different arterial segments from coronary arteries to iliac arteries.

CONCLUSION

Eosinophils release cationic proteins that can promote SMC calcification and atherogenesis using the BMPR-1A/1B-Smad-1/5/8-Runx2 signalling pathway.

Análisis clínico e histopatológico de la prevalencia de enfermedades cardiacas en muerte súbita. Estudio en autopsias

Introducción: un evento de muerte súbita supone un gran impacto para la sociedad, siendo importante su estudio para aportar conocimiento y fortalecer estrategias de promoción y prevención. Objetivo: determinar la prevalencia de los diagnósticos anatomopatológicos cardiacos definitivos y los hallazgos histopatológicos asociados con la muerte súbita de origen cardíaco en los pacientes sometidos a autopsias clínicas realizadas en el Hospital de San José de Bogotá DC, Colombia, durante el período 2015 a 2018. Métodos: estudio descriptivo de corte transversal retrospectivo en pacientes a quienes se les realizó autopsia con diagnóstico de muerte súbita de origen cardiovascular en el servicio de patología del Hospital de San José, Bogotá DC, Colombia. Resultados: se incluyeron 178 autopsias con diagnóstico de muerte súbita cardíaca. El promedio global de edad fue 56.1 años (DE: 15.06) con una relación hombre-mujer de 3:1. El hallazgo macroscópico más frecuente fue cardiomegalia (promedio 428.1 g (DE 112.8), acompañado de la presencia de coronariopatía esclerótica (p=0.000) con obstrucción de la luz de las arterias coronarias mayores de 80% (p=0.037). Conclusiones: los diagnósticos anatomopatológicos definitivos prevalentes en la muerte súbita cardiaca fueron cardiopatía isquémica crónica complicada (65%) e infarto agudo de miocardio (16%), datos similares a los reportados a nivel mundial. La cardiomegalia es un hallazgo frecuente que debe valorarse en forma cuidadosa.