Ischaemia-modified albumin elevation after percutaneous coronary intervention reflects albumin concentration rather than ischaemia

Abstract

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.