Abstract
BACKGROUND: Acute myocardial infarction (AMI) is one of the most deleterious conditions leading to cardiovascular diseases and mortality. The importance of an early and accurate diagnosis assures immediate medical treatments, which are fundamental to reduce mortality and improve prognoses. AMI is associated to an inflammatory response which includes the increase of circulating inflammatory cytokines, chemokines and immune cell activation. This study aimed to identify which are the very early immune-related biomarkers that may be used as predictors of myocardial infarction severity. In order to mimic the pathophysiological events involved in human myocardial infarction, a temporary occlusion (90 min) of the mid-left anterior descending coronary artery was performed in a swine animal model. RESULTS: Lymphocyte subsets analysis in peripheral blood revealed significant alterations in CD4+/CD8+ ratio and naïve and effector/memory T cell percentages at 1 h post-myocardial infarction. Changes in TH1/TH2-related cytokine, monocyte and neutrophil markers gene expression were observed in peripheral blood lymphocytes, as well. Additionally, significant correlations between cardiac parameters (cardiac enzymes, left ventricular ejection fraction and % infarct) and blood-derived parameters (cytokine expression and lymphocyte subset distribution) were found. CONCLUSIONS: Peripheral blood lymphocyte alterations are easily and swiftly detectable, so they may be good biomarkers for a very early prognosis and to predict myocardial infarction severity.