缺血修饰白蛋白对急性心肌缺血早期诊断价值的探讨

目的探讨缺血修饰白蛋白（IMA）测定对急性心肌缺血的早期诊断价值。方法采用白蛋白钴结合试验检测830例健康体检者（健康对照组）、492例急性冠状动脉综合征患者（ACS组）、74例单纯性高血压病患者（高血压组）、78例病毒性心肌炎患者（病毒性心肌炎组）、395例急性胸痛者（急性胸痛组,包括急诊ACS患者133例与随诊胸痛患者262例）和68例接受经皮冠状动脉介入治疗术患者（PCI组）血清或血浆IMA水平,并对其中急诊ACS患者进行IMA水平动态观察及血清肌钙蛋白I（cTnI）和心电图检测。结果根据ROC曲线,当临界值为0．45时综合评价最佳。ACS组和病毒性心肌炎组IMA水平分别为（0．55±0．11）吸光度单位（ABSU）和（0．38±0．11）ABSU,高于健康对照组（0．34±0．08）ABSU,P〈0．05],且ACS组和病毒性心肌炎组之间IMA差异有统计学意义（P〈0．05）。急性胸痛组中急诊ACS患者IMA水平及阳性率分别为（0．54±0．12）ABSU和77．4％,高于随诊者的（0．44±0．12）ABSU和39．3％（P〈0．01）。在133例急诊ACS患者中,首诊1h内IMA阳性率为82．O％,高于同期cTnI阳性率40．6％（P〈0．01）,就诊后6—24hIMA与cTnI水平及阳性率较首诊1h内显著升高（P〈0．01）。在72例急性胸痛发作3h内入院且cTnI均为阴性的ACS患者中,首诊IMA阳性率为86．1％,心电图阳性率为72．2％,两者联合测定阳性率为93．1％。PCI术后即刻患者动脉血浆IMA水平较术前IMA明显升高（P〈0．05）。首诊ACS患者IMA水平高于临界值,于入院1天达峰值,且持续升高,后缓慢下降,入院14天IMA均值接近正常水平。结论IMA早期诊断急性心肌缺血具有临床应用价值。

Diagnostic value of ischemia-modified albumin in patients with acute coronary syndrome

OBJECTIVE: To investigate the diagnostic value of ischemia-modified albumin (IMA) for patients with acute coronary syndrome (ACS). METHODS: We 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. RESULTS: The 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. CONCLUSIONS: IMA was a useful biochemical marker for the early diagnosis of ACS.