Association of Serum Gamma Glutamyl Transferase Level with Acute Coronary Syndrome and Its Correlation with Major Adverse Cardiovascular Outcomes - A Single Center Cross Sectional Study from a Tertiary Care Centre in Kerala
BACKGROUND Gamma glutamyl transferase (GGT) is a biomarker elevated in various cardiovascular diseases due to oxidation mediated free radical damage. It has been recently used in patients presenting with acute coronary syndromes (ACS) for predicting major adverse cardiovascular events and in hospital adverse outcomes. The application of gamma glutamyl transferase to the traditional set of biomarkers like troponin I and T, creatinine kinase-MB (CKMB) adds to the value that it helps in reclassifying the patients into high and low risk and plan the appropriate treatment strategy. METHODS Patients presenting with acute coronary syndromes were classified into STEMI (ST elevation myocardial infarction), NSTEMI (Non-ST elevation myocardial infarction) and unstable angina based on cardiac biomarkers and electrocardiographic changes. Serum gamma glutamyl transferase of these patients were measured by photo spectrometry and were monitored for 5 days for major adverse cardiovascular events. RESULTS Of the study population (N = 210), 41 % presented with STEMI, 24 % unstable angina, 25 % NSTEMI. The normal range of GGT in our study population was 15 - 70 U/l. values more than 70 U/l was considered raised GGT major adverse cardiac events (MACE) was present in 35 % of the study population. 58 % of the patients with MACE had raised GGT (> 70 U/l) which was statistically significant (P < 0.001). The ROC (receiver operator characteristic curve) for GGT to predict MACE was to the left of the reference line and the area under the curve (AUC) was 0.915. The optimal cut-off for GGT to predict MACE from our study was 50.5 with a sensitivity and specificity of 0.813 and 0.868 respectively. CONCLUSIONS Raised GGT was significantly associated with MACE and in hospital adverse outcomes (ventricular arrythmias, heart failure, recurrent angina). GGT can be used as a prognostic marker in patients presenting with ACS. KEYWORDS Gamma Glutamyl Transferase, Acute Coronary Syndromes, St Elevation Myocardial Infarction, Non-ST Elevation Myocardial Infarction, Unstable Angina