Ischemia modified albumin in relation to pharmacologic stress testing in coronary artery disease.

ABSTRACT

BACKGROUND: Ischemia modified albumin (IMA) is considered a biomarker of myocardial ischemia. We sought to investigate whether IMA plasma levels change during pharmacological stress test, in patients with stable coronary artery disease. METHODS: We studied 37 patients undergoing non-invasive evaluation with a pharmacological stress test, either with radionuclide myocardial perfusion imaging with adenosine or stress echocardiography with dobutamine. Peripheral venous samples were collected before the stress test (baseline), at the end of adenosine infusion or at the peak dose of dobutamine and 60 min after the completion of the stress test for IMA measurement. RESULTS: IMA plasma levels significantly increased at peak vs. baseline (91.28+/-9.59 U/ml vs. 97.97+/-9.69 U/ml, p<0.0001) and subsequently, decreased significantly at 60 min compared to peak (97.97+/-9.69 U/ml vs. 94+/-15.22 U/ml, p=0.016), returning to values similar to those at baseline (p=0.134). Similarly, in patients with a negative stress test, IMA significantly increased at peak compared to baseline (91.08+/-10.03 U/ml vs. 99.58+/-8.43 U/ml, p=0.006) and returned to baseline at 60 min (99.58+/-8.43 U/ml vs. 91.83+/-7.93 U/ml, p=0.019), the 60 minute levels being similar to baseline values (p=0.212). Conversely, in patients with a positive stress test, IMA significantly increased at peak compared to baseline (91.38+/-10.13 U/ml vs. 97.17+/-10.34 U/ml, p=0.006) and although decreased at 1 h, this did not reach statistical significance compared either to the baseline or to the peak values (95.04+/-17.76 U/ml vs. 91.38+/-10.13 U/ml, p=0.315 and 95.04+/-17.76 U/ml vs. 97.17+/-10.34 U/ml, p=0.235, respectively). CONCLUSION: IMA plasma levels change significantly during pharmacologic stress testing, in patients with coronary artery disease, but with no difference between the positive and the negative tests.