Ischaemic Skeletal Muscle Increases Serum Ischaemia Modified Albumin

Abstract Objectives Ischaemia modified albumin (IMA) has been used as a marker of myocardial ischaemia but little is known about its production during ischaemia of other tissues. The clinical models of patients with intermittent claudication and major arterial surgery were used to investigate IMA production from ischaemic skeletal muscle. Design Prospective clinical study. Materials and methods IMA was measured pre-operatively, at end ischaemia, and 5 min, 4, 24, 48, 72 and 144 h post-surgery in patients undergoing (a) revascularisation for intermittent claudication (IC, n =15), (b) abdominal aortic aneurysm repair (AAA, n =12) and controls ( n =16). Results The median pre-operative IMA concentration in IC patients was significantly higher than the AAA group (88.3 versus 83.5 U/ml, p =0.036) and controls (88.3 versus 80.3 U/ml, p =0.031). IMA concentrations increased significantly during arterial clamping in both IC and AAA groups (88.3 versus 120.0 U/ml, p =0.001; 83.5 versus 118.8 U/ml, p =0.002, respectively) consistent with increased skeletal muscle ischaemia. In contrast, there was only a mild perioperative increase in the controls (80.3 versus 91.6 U/ml, p =0.012). Conclusions Patients with intermittent claudication have significantly elevated IMA and skeletal muscle ischaemia during arterial surgery results in significantly increased circulating IMA. When IMA is used to detect myocardial ischaemia, ischaemic skeletal muscle must be excluded.