Early Diagnosis of Acute Coronary Syndrome with Sensitive Troponin I and Ischemia Modified Albumin

Background: In this study we compared the diagnostic performance of serum ischemia modified albumin (IMA) and sensitive cardiac troponin I (cTnI) assay for the detection of acute coronary syndrome (ACS) in patients presenting to the emergency department (ED) with acute chest pain.
Methods: A prospective study was conducted on 123 patients presenting to the ED within three hours of acute chest pain. A 12-lead ECG was recorded and IMA and cTnI were measured on arrival at the ED. After diagnostic testing, the patients were classified as either ACS (n=70) or non- ACS (n= 53). The results of IMA, ECG, and cTnI, alone and in combination, were correlated with final diagnoses.
Results: IMA showed higher sensitivity (84%) and negative predictive value (NPV, 88%) compared to cTnI (sensitivity 42%, NPV 66%) and ECG (sensitivity 58%, NPV 74%). Combined use of IMA, cTnI and ECG significantly improved the sensitivity (96%, P<0.05) and NPV (96%) of IMA. The diagnostic performance of IMA was similar in the case of non-ST-segment-elevation ACS (sensitivity 80%, NPV 80%). The sensitivity and specificity of IMA for diagnosis of acute myocardial infarction (AMI) were 88% and 48%, respectively.
Conclusion: Measuring IMA at the time of ED admission improves the early diagnosis of ACS and non-ST-segment-elevation ACS in patients with acute chest pain. However, the test is not an effective tool for diagnosis of AMI in patients with chest pain presenting to ED.