Demir H, Topkaya B C, Erbay A R, Dogan M, Yücel D
Department of Clinical Biochemistry, Ankara Training and Research Hospital, Ministry of Health, Cebeci, Ankara 06340, Turkey.
Ann Clin Biochem. 2009 Jul;46(Pt 4):327-31. doi: 10.1258/acb.2009.008238. Epub 2009 Jun 1.
Percutaneous coronary intervention (PCI) is accepted as a model of myocardial ischaemia in studies of ischaemia markers, especially of ischaemia-modified albumin (IMA). However, there is concern that IMA levels may reflect changes in albumin concentrations rather than myocardial ischaemia also during PCI.
Twenty-one consecutive patients (17 men and 4 women) undergoing single-vessel percutaneous coronary angioplasty were enrolled in the study. IMA and albumin levels were measured together with myoglobin, creatine kinase 2 and cardiac troponin I, before (Group 1), immediately after (Group 2) and 6 h after (Group 3) the procedure of PCI.
The IMA levels of Group 2 were significantly higher than those of Group 1 and Group 3 (P < 0.05 for both). However, correction of IMA by multiplying with the (individual albumin concentration of the patient/median albumin concentration of Group 1) ratio gave no statistical differences between the groups (P > 0.05). There were strong negative correlations between IMA levels and albumin concentrations within individual groups (r = -0.757, P < 0.001; r = -0.712, P < 0.001; and r = -0.705, P < 0.001 for Group 1, Group 2 and Group 3, respectively).
The results confirm the close dependency of IMA results on albumin concentrations. Therefore, IMA results reflect albumin concentrations rather than myocardial ischaemia also in PCI. This situation and lack of standard reference materials for the albumin cobalt binding assay can lessen the diagnostic performance of IMA.
在缺血标志物研究中,尤其是缺血修饰白蛋白(IMA)的研究中,经皮冠状动脉介入治疗(PCI)被视为心肌缺血的一种模型。然而,有人担心在PCI过程中IMA水平可能反映的是白蛋白浓度的变化而非心肌缺血。
连续纳入21例接受单支血管经皮冠状动脉血管成形术的患者(17例男性和4例女性)。在PCI手术前(第1组)、术后即刻(第2组)和术后6小时(第3组),同时测量IMA、白蛋白水平以及肌红蛋白、肌酸激酶同工酶2和心肌肌钙蛋白I。
第2组的IMA水平显著高于第1组和第3组(两组比较P均<0.05)。然而,用(患者个体白蛋白浓度/第1组白蛋白浓度中位数)的比值乘以IMA进行校正后,各组之间无统计学差异(P>0.05)。各组内IMA水平与白蛋白浓度之间均存在强负相关(第1组、第2组和第3组的r值分别为-0.757,P<0.001;-0.712,P<0.001;-0.705,P<0.001)。
结果证实了IMA结果与白蛋白浓度密切相关。因此,在PCI中IMA结果反映的是白蛋白浓度而非心肌缺血。这种情况以及白蛋白钴结合试验缺乏标准参考物质可能会降低IMA的诊断性能。