Association of Serum Gamma-Glutamyl Transferase (GGT) Levels in Acute Myocardial Infarction Patients and their Outcome

BACKGROUND: Acute myocardial infarction is the most common diagnosis in hospitalized patients in the developed and developing countries. About half of the acute myocardial infarction related deaths occur before the patient reaches the hospital. Most common cause for acute myocardial infarction is rupture of an atheromatous plaque. Gamma Glutamyl Transferase (GGT) is a membrane bound enzyme usually located in all cells plays an important role in catabolism of glutathione thereby releasing free radicals which stimulates prooxidant reactions, thus causing oxidative stress in the cells leading to the formation of atherosclerosis by lipoprotein peroxidation. So the levels of GGT will be increased in atherosclerotic disease, most commonly Myocardial infarction. OBJECTIVE: To evaluate the association of serum Gamma Glutamyl Transferase in Acute Myocardial Infarction patients admitted at GRH, Madurai and their outcomes. MATERIALS AND METHODS: The study was conducted to acute myocardial infarction patients who were admitted at Government Rajaji Hospital, Madurai. The diagnosis of acute myocardial infarction was based on “Third Universal Definition of Myocardial Infarction”. Fifty patients participated in the study. In all these patients serum GGT and serum CK-MB levels were estimated as soon as they were diagnosed. Serum gamma glutamyltransferase was measured by calorimetric kinetic assay. Serum CK-MB was measured by spectrophotometric assays. All analysis were done using SPSS software version 16. Shapiro wilks normality test, Mann–Whitney U-test, Spearman rank correlation coefficient were used for the data analysis. RESULTS: Serum levels of GGT were elevated in almost all acute myocardial infarction patients. Statistically significant linear correlation was present between the levels of GGT and the percentage of stenotic lesion in the coronary angiography of myocardial infarction patients with p value of about 0.001(<0.05). With ROC curve, the cut-off value of GGT for atherosclerotic lesion of myocardial infarction was found which was ≥ 52.5 U/L with sensitivity of 72 and specificity of 71.4. CONCLUSION: Thus higher GGT levels reflects the atherosclerotic burden in acute myocardial infarction patients. So GGT can be used as a marker of atherosclerosis in acute myocardial infarction patients thereby diagnosing premature coronary artery disease.