The Activity Of Autophagy Biomarkers In Acute Myocardial Infarction

Purpose: We aimed to evaluate the activity of autophagy in patients with AMI. Furthermore, this study analyzed the associations of autophagy biomarkers with the traditional cardiac biomarkers, echocardiographic left ventricular ejection fraction (LVEF) and the defect size of myocardial SPECT. Methods: AMI patients with urgent coronary revascularization and controls who underwent coronary angiography without significant coronary artery stenosis were enrolled prospectively. We obtained the serum of patients from peripheral artery and coronary artery before coronary revascularization. Levels of LC3-II, ATG5, Beclin 1 and M30 were quantified by ELISA in the serum from 71 AMI patients and 46 controls. Results: AMI patients had significant higher concentrations of autophagy biomarkers such as LC3-II (217.0±87.5 vs. 58.1±53.2 ng/ml; 218.6±72.4 vs. 58.7±53.7 ng/ml; p<0.001), ATG5 (183.7±100.1 vs. 35.8±34.2; 169.6±85.3 vs. 38.3±43.1; p<0.001), and Beclin 1 (194.9±86.2 vs. 62.0±53.5; 178.0±67.1 vs. 58.7±50.1; p<0.001) in peripheral artery and coronary artery. All autophagy biomarkers in both arteries had strong positive correlations with traditional cardiac biomarkers including CK-MB, Troponin T, and NT-proBNP. Especially, LC3-II in coronary artery was significantly correlated with the defect size (%) on myocardial SPECT (r s =0.333, p=0.010) in AMI patients. Conclusions: Autophagy biomarkers were significantly higher in AMI patients than in controls. Autophagy biomarkers had significant positive correlations with the traditional cardiac biomarker. LC3-II was significantly correlated with the LV defect size due to myocardial injury in AMI patients.