Objective To study the diagnostic value of ischaemia modified albumin (IMA) for unstable angina (UA).

Methods The level of blood serum IMA of UA patient, stable angina (SA) patient and the non- coronary heart disease group (CHD) were detectioned by IMA reagent kit (Changsha YIKANG Technical Co. Ltd). To calculate the IMA diagnostic sensitivity, ecificity positive predictive value (PPV) and negative predictive value (NPV) of UA. IMA goes by albumin cobalt binding (ACB), IMA value was denoted by ABC value. The lower ABC value was, the higher free cobaltion (Co²⁺) concentration was, to indicate higher IMA. ABC value was shown by U/ml, one U was defined as 1 μg Co²⁺ absorbed by albumin in 1 ml serum. The optimal cutoff point (cutoff)as distinguishing UA from The control group was obtain By receiver operator characteristive (ROC).

Results 1. ABC value of UA group (72 patients) was 62.80±9.56 U/ml, SA group (43 patiens) was 73.56±6.43, non-CHD group (39 patients) was 76.13±7.25. The ABC value in the UA group was obviously lower than the SA group and the non-CHD group (p<0.01), but the SA group was not difference from the non-CHD group (p>0.05). The ABC value in the UA group within 6 h (43 patients) were obviously lower than that in the period from 6 to 12 h (29 patients) (p<0.01), the latter was also obviously lower than the non-CHD group (p<0.01). That indicated: The level of IMA in the group of UA patients within 12 h was obviously higher than the SA group and the non-CHD group (p<0.01), which was more significantly higher within 6 h. 2. The area under cure (AUC) was 0.945, cutoff point was 66.3 U/ml, the sensitivity of the diagnosis of UA patient onset within 12 h is 91.67 %, the specifity is 82.05%., PPV is 90.41%, NPV was 84.21%. That indicated : the sensitivity and PPV of IMA diagnosis of UA patient onset within 12 h were high, the specifity and NPV were lower.

Conclusion IMA becomes possibly the sensitive biochemical marker for myocardial ischaemia and is applyed diagnosing UA in the earlier period.