Serum markers of tissue damage and oxidative stress in patients with acute myocardial infarction

Acute myocardial infarction (AMI) is a critical cardiovascular event due to its associated complications and mortality. The pathogenesis of AMI is complex and usually an array of biomarkers is needed for its diagnosis and prognosis. In this study, we determined serum levels of enzymatic markers of tissue damage including aspartate aminotransferase (AST), lactate dehydrogenase (LDH) and creatine kinase (CK) and the markers of oxidative stress including glutathione (GSH) and malondialdehyde (MDA) in 128 AMI patients and 121 normal subjects. We also studied correlations between the above biomarkers and troponinT, age, gender, smoking and hypertension. The level of LDH was significantly higher in AMI patients (246.49 ± 9.30 U/L) as compared to control subjects (181.63 ± 5.77 U/L). Although the levels of serum AST (29.07 ± 2.06 versus 22.51 ± 0.80 U/L) and CK (133.78 ± 15.23 versus 121.30 ± 11.93 U/L) were higher in AMI patients than controls, they did not reach the significance level. There was a significant decrease in serum GSH and increase in MDA levels in AMI patients as compared to controls. There was no significant correlation between any of the three enzymatic markers of the tissue damage and age indicating their biomarker value irrespective of the age group. However, gender appeared to be a confounding factor while interpreting AST and CK as it showed a significantly negative correlation with the female gender. There were highly significant correlations between troponin-T and AST, LDH or CK. Although smoking was not correlated with any of the biomarkers studied, hypertension showed significant correlation with CK levels. In conclusion, serum LDH is significantly increased in AMI patients that can be regarded as an early predictor of tissue damage. Both the markers of oxidative stress including GSH and MDA are significantly altered in AMI so they can be used to evaluate oxidative stress in these patients. Further studies are warranted to evaluate the prognostic value of these markers in AMI patients.