Ischemia-modified albumin in relation to exercise stress testing

OBJECTIVES We examined whether ischemia-modified albumin (IMA) plasma levels change during exercise stress testing (EST) in patients with known coronary artery disease and whether the induced changes differ between positive and negative exercise tests. BACKGROUND Ischemia modified albumin is considered a marker of myocardial ischemia and increases after coronary angioplasty and in acute coronary syndromes. METHODS We studied 40 consecutive patients with established coronary artery disease who underwent EST. Venous samples, for IMA measurement, were collected before the stress test (baseline), at peak exercise, and 60 min after the completion of the exercise test. RESULTS There was significant difference in the IMA values at the 3 prespecified time points (p 0.012), whereas there was no interaction between the IMA changes and the result of the stress test, whether positive or negative (p for the interaction term = 0.94). Baseline, peak EST, and post-EST IMA levels were similar in patients with positive and negative exercise tests (p = 0.61). The IMA significantly decreased at peak exercise compared with baseline values in positive (p < 0.0001) and in negative EST (p = 0.012). Moreover, IMA concentration increased 60 min after EST compared with peak-EST values in positive (p < 0.0001) and in negative tests (p = 0.003), returning to pre-EST levels in both groups. CONCLUSIONS The IMA plasma levels change significantly during exercise testing in patients with coronary artery disease, but there is no difference between positive and negative stress tests; this possibly implies that the observed changes do not reflect myocardial ischemia.