OBJECTIVETo investigate the diagnostic value of ischemia-modified albumin (IMA) for patients with acute coronary syndrome (ACS).

METHODSWe detected the IMA levels by albumin cobalt-binding (ACB) test and observed its dynamic changes in 492 patients with ACS, 74 patients with high blood pressure, 78 patients with viral myocarditis (VMC), 395 patients with acute chest pain (133 patients with acute ACS and 262 follow-up patients due to chest pain), 68 patients underwent percutaneous coronary intervention (PCI) and 830 healthy controls. Cardiac troponin I (cTnI) levels were assayed and electrocardiogram (ECG) recorded in patients with ACS.

RESULTSThe optimal diagnostic cutoff point for IMA in this study population was found to be 0.45 ABSU by ROC analysis. The IMA level (ABSU) in ACS group (0.55 +/- 0.11) was significantly higher than that in VMC group (0.38 +/- 0.11) and IMA levels in ACS and VMC groups were both higher than that in control and high blood pressure groups (0.34 +/- 0.08 and 0.35 +/- 0.08, all P < 0.05). IMA levels and the positive rates in patients with ACS were significantly higher (0.54 +/- 0.12 vs 0.44 +/- 0.12, 77.4% vs 39.3%, all P < 0.01) than those in chest pain follow-up group. In 133 patients with ACS, positive rate for IMA was significantly higher than that for cTnI within 1 h of admission (82.0% vs 40.6%, P < 0.01), and was similar at 6 - 24 h after admission (96.2% vs. 95.5%, P > 0.05). In 72 patients presenting to the emergency center within 3 h of acute chest pain and with negative cTnI, positive rate for IMA was 86.1% and for ECG 72.2%, the sensitivity for ACS diagnosis rised to 93.1% with both methods. The IMA leve was higher immediately after PCI than that before PCI (P < 0.05). IMA levels peaked 1d after hospitalization, then decreased gradually and returned to normal 14 days later.

CONCLUSIONSIMA was a useful biochemical marker for the early diagnosis of ACS.