Application of albumin-adjusted ischemia modified albumin index as an early screening marker for acute coronary syndrome

BACKGROUND: Existing cardiac markers are not sensitive for reversible myocardial ischemia. Ischemia modified albumin (IMA) has recently been shown to be an early and sensitive marker of myocardial ischemia. We established a newly standardized, albumin-adjusted IMA index that was more sensitive and accurate than the conventional IMA value. METHODS: We enrolled 413 consecutive patients with symptoms suggestive of acute coronary syndrome (ACS). All patients were classified to either the ACS group (n=129) or 4 other groups (n=284). The ideal cutoff value of IMA was calculated by the receiver operating characteristic (ROC) curve analysis. The albumin-adjusted IMA index was calculated from the results of correlation assay between serum albumin concentration and IMA value and re-applied. RESULTS: The sensitivity and specificity of IMA for ACS were 93.0% and 35.6%, respectively, at 85.0 U/ml. IMA had a negative linear relationship with serum albumin and albumin-adjusted IMA index was calculated by using the following equation [IMA index=serum albumin conc. (g/dl) x 23+IMA (U/ml)-100]. The sensitivity and specificity were 98.4% and 34.5%, respectively, at IMA index of 83.4. CONCLUSIONS: The use of the calculated albumin-adjusted IMA index is recommended to increase the sensitivity of the ACS diagnosis although IMA is a sensitive marker for the identification of ACS.