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.