Characterization and implications of the dynamics of eosinophils in blood and in the infarcted myocardium after coronary reperfusion

Abstract

ObjectiveWe characterized the dynamics of eosinophils in blood and in the infarcted myocardium in patients and in a swine model of reperfused myocardial infarction (MI). The association of eosinophil dynamics with various outcomes was assessed.MethodsSerial eosinophil count and pre-discharge cardiac magnetic resonance were carried out in a prospective series of 620 patients with a first ST-elevation MI. In a swine model of reperfused MI, the dynamics of circulating eosinophils and their presence in the infarcted myocardium were determined. In autopsies from chronic MI patients, eosinophils were quantified.ResultsPatient eosinophil count sharply decreased 12h post-reperfusion compared to arrival. A lower minimum eosinophil count was associated with more extensive edema, microvascular obstruction, and infarct size as measured by cardiac magnetic resonance, and also with a higher rate of cardiac events (death, re-infarction, or heart failure) during follow-up. In the experimental model, eosinophil count boosted during ischemia and dropped back immediately post-reperfusion. Myocardial samples revealed progressive eosinophil migration into the infarcted myocardium, especially areas with microvascular obstruction. Markers of eosinophil maturation and survival (interleukin-5), degranulation (eosinophil cationic protein) and migration (eotoxin-1) were detected in the blood of patients, and in porcine myocardium. Eosinophil infiltration was detected in autopsies from chronic MI patients.ConclusionEosinopenia post-MI was associated with an impaired cardiac structure and adverse events. The decay in circulating eosinophils soon after reperfusion mirrors their migration into the infarcted myocardium, as reflected by their presence in heart samples from swine and patients. Further studies are needed to understanding this unexplored pathway and its therapeutic implications.

Sex differences in leukocyte profile in ST-elevation myocardial infarction patients

“…Limited is known about sex differences in eosinophils in STEMI patients. Previous research studied eosinophil levels in 620 STEMI patients and observed an association between a decrease in eosinophils and higher risk of major adverse events 18 . However, analyses were not stratified by sex.…”

Magnetic resonance microscopy and correlative histopathology of the infarcted heart

“…A 2.5 × 15 mm over-the-wire angioplasty balloon was inflated to 6 atm immediately distal to the first diagonal branch and coronary artery occlusion was confirmed by contrast injection and by electrocardiographic ST-segment elevation. Additional details on our experimental models can be consulted elsewhere 14,25,26 .…”

Microvascular Obstruction in ST-Segment Elevation Myocardial Infarction: Looking Back to Move Forward. Focus on CMR

“…After MI, inflammation is a physiological and necessary response that initiates repair. However, when out of control, this process can lead to unnecessary myocardial and microvascular damage [15,16]. Neutrophils, via aggregation and formation of neutrophil extracellular traps, decisively participate in MVO progression [17].…”

“…In the field of biomarkers, an important and early rise in troponin is associated with more extensive MVO [20]. Regarding white blood cells, increases in innate immunity cell counts (neutrophils and monocytes) and decreases in adaptive-effector immunity cell counts (lymphocytes and eosinophils) are associated with MVO [15,16].…”