Clinical Significance Of Ischemia Modified Albumin In Early Diagnosis Of Cardiac Ischemia

ObjectiveTo investigate the early diagnostic value of ischemia modified albumin (IMA) for cardiac ischemia.MethodsSerum IMA levels were detected by albumin-cobalt binding test (ACB test). The decrease of ACB values means the increase of serum IMA levels. 50 ACS patients suffering from chest pain within 3 hours, 50 patents with stable coronary artery diseases and 50 controls were included in the study. After admission, a18-lead electrocardiogram (ECG) was recorded and blood samples were taken for IMA and cardiac troponin T (cTnT) measurement in all ACS subjects immediately. All patients underwent standard triage, diagnostic procedures and treatment. ACB values were measured 24 hours later in the patients who received PCI treatment and 7 days later in the patients who received drug therapy. Receiver operating characteristic curve (ROC) analysis was used to determine the optimal cutoff value of this assay for identifying cardiac ischemia individuals from nonischemia individuals.Results1. The ACB value of ACS group [(79.62±9.20)U/ml] was significant lower than that of stable coronary artery disease group [(90.88±7.05) U/ml] and that of nonischemia individuals [(99.52±3.62) U/ml] (P < 0.05). The concentration of cTnT and CK-MB had no significant difference in the 3 groups.2. There was no significant difference of ACB value between the UA group [(80.96±8.63)U/ml] and the AMI group [(79.50±10.80) U/ml] (P>0.05).3. A cutoff value of ACB value of 94U/ml was found by receiver operating characteristic curve analysis. The area under the curve (AUC) was 0.930(95%CI 0.877~0.965). The sensitivity and specificity of this cutoff value to identify the patients of cardiac ischemia were 83.00% (95%CI 74.20~89.8) and 94.00% (95%CI 83.40~93.70) respectively. Positive likelihood ratio and negative likelihood ratio were 13.83(95%CI 12.4~15.5)and 0.18(95%CI 0.06~0.6)respectively. Sensitivity of this value for the identification of cardiac ischemia was 83.00% as compared with 67.00% of ECG and 17.00% of cTnT.4. The ACB value in ACS group was significant difference before and after drug therapy [(79.18±10.0)U/ml vs (90.36±6.40)U/ml, (P < 0.001) ]. The ACB value in stable coronary artery disease group was also significant difference before and after drug therapy [(90.88±7.06)U/ml vs (95.84±4.87) U/ml, (P < 0.001) ].5. The ACB value before PCI treatment [(79.68±10.06)U/ml] was significant lower than that after the treatment[(92.90±9.79)U/ml] (P < 0.001).ConclusionsSerum IMA assessment is valuable for early diagnosis of cardiac ischemia, especially in ACS patients. But it is not a good marker for early differentiation of cardic ischemia from acute myocardial infarction.