The Clinical Evaluation Role of Ischaemia Modified Albumin in Diagnosis of Acute Coronary Syndrome: Unstable Angina to Myocardial Infarction

Introduction: Acute Coronary Syndrome (ACS) includes a spectrum of disorders ranging from unstable angina to myocardial infarction. Since ACS is an important cause of mortality in the world, early diagnosis of the disease is very important. Ischaemia Modified Albumin (IMA) is an ischaemia biomarker that has been approved by the US Food and Drug administration and has clinical application. Although many studies have been done on IMA as a biomarker in ACS patients, role of IMA for differentiating patients with unstable angina, Non ST-Segment Elevation Myocardial Infarction (NSTEMI) and ST-Segment Elevation Myocardial Infarction (STEMI) requires further study. Aim: To assess diagnostic role of IMA in ACS patients and evaluate correlation between IMA and necrotic biomarkers such as cardiac Troponin I (cTnI) and Creatine kinase-myoglobin binding (CKmb) in ACS patients. Materials and Methods: The study included 75 subjects with ACS, who were divided into three groups of twenty-five patients each: Unstable angina, NSTEMI and Myocardial Infarction (MI) and 25 healthy people as control. They were enrolled into the study from the Fatemeh Zahra Heart Center, Sari, Iran, between November 2015 and October 2016. IMA was measured by the Cobalt-Albumin Binding (CAB) assay, cTnI was measured by rapid immunoassay and CKmb was estimated utilising colorometric enzyme method by commercial kits. The correlation between IMA and necrotic biomarkers was determined using a Pearson correlation analysis. Receiver Operator Characteristic (ROC) curve was used for optimal cut-off the IMA. Results: IMA levels in unstable angina patients were significantly higher than NSTEMI and MI (p<0.001). While there was no significant difference in IMA levels between NSTEMI and MI (p=0.675). Furthermore, no statistically significant correlation was found between IMA and necrotic biomarkers in ACS patients (p>0.5, r=0.25). The area under the ROC curve of IMA for ACS patients was 0.783. The sensitivity, specificity, Positive Predictive Value (PPV) and Negative Predictive Value (NPV) of IMA was 74.7%, 72%, 88.9% and 48.6% respectively. Conclusion: IMA is a useful biomarker in diagnosis of ACS especially unstable angina patients and there is no significant correlation between IMA and necrotic biomarkers (cTnI and CKmb) in ASC patients.