Increased ischaemia modified albumin following coronary artery bypass grafting

BACKGROUND: Any increase of cardiac biomarkers after coronary artery bypass grafting (CABG) indicates myocyte necrosis and is likely to be related to an impaired outcome. We investigated whether ischaemia-modified albumin (IMA), a biomarker of ischaemia, is also raised following CABG. METHODS: We studied 50 stable consecutive patients undergoing elective isolated CABG on cardiopulmonary bypass, of whom 46 were men and four women, aged 64 +/- 9 years. Blood samples were obtained the day before the operation (pre-op) as well as immediately after the operation, 24 h postoperatively (post-op) and the fourth day post-op and assayed for creatine kinase, the MB isoenzyme of creatine kinase, cardiac troponin-I, albumin and IMA. RESULTS: The typical rising and falling pattern of myocardial necrosis of all three cardiac enzymes was observed post-op (p <0.0001). IMA increased significantly following CABG at all three time points (113 +/- 43, 106.7 +/- 22.6 and 110.2 +/- 12.5 U ml(-1), respectively) compared with pre-op values (91.7 +/- 10.5 U ml(-1)), (p <0.0001); the sample immediately post-op was significantly higher compared with the following samples (immediately post-op vs 24 h, p = 0.008 and immediately post-op vs 4 days, p = 0.03, with no significant difference between the last two). IMA level changes during the study course were independent of the albumin changes. Haemoglobin decreased significantly post-op (p <0.0001 vs baseline) whereas serum creatinine did not differ during the study period. CONCLUSIONS: IMA increases significantly following CABG but whether or not this carries a prognostic significance remains to be elucidated.