Clinical Usefulness of Ischemia Modified Albumin in Acute Coronary Syndrome

Kang, So Young; Suh, Jin Tae; Lee, WooIn

Abstract

BACKGROUND
Diagnosis of myocardial ischemia in patients with symptoms suggesting acute coronary syndrome (ACS) is often difficult because of absence of well-defined markers to identify patients with myocardial ischemia. Recently, ischemia modified albumin (IMA) has been used as a sensitive and early marker of myocardial ischemia. We studied the clinical usefulness of IMA for detection of ACS with traditional cardiac markers such as CK-MB and cTnI. METHODS: We assessed 87 patients suspected of having ACS. This study evaluated IMA in conjunction with CK-MB and cTnI. All patients were reviewed by a cardiologist and classified into ACS (n=27), cerebrovascular disease (CVD) (n=11), and non-ACS (n=49) groups. Statistical analysis was performed with receiver operating characteristics (ROC) curve analysis and ANOVA with a multiple comparison test. RESULTS: ROC curves showed that IMA was more sensitive but less specific than cTnI and CK-MB, and that the optimal cutoff value of IMA was 110 U/mL for the detection of ACS. Particularly, when tested within 4 hours of the onset of symptoms, IMA detected 100% of the patients with ACS, including even those with normal electrocardiogram (ECG) and/or cTnI; however, 50% of the patients with positive IMA results (> or = cutoff value) had other conditions such as CVD including mainly ischemic stroke, cancer, trauma, and fat embolism, etc. On the other hand, most of the patients with negative IMA results were not ACS. CONCLUSIONS: IMA is a useful early marker for the identification of ACS, especially in patients with myocardial ischemia before or without MI with normal ECG and/or cTnI. A positive result of IMA is not necessarily to indicate where the ischemia has occurred; however, a negative IMA result can rule out ACS in the early phase of symptom onset.