Kinetics of Ischemia-Modified Albumin Following Exercise-Induced Myocardial Ischemia

Background: Ischemia-modified albumin (IMA) is a potentially valuable biochemical marker of myocardial ischemia. The aim of our study was to define the kinetics and to determine the diagnostic value of IMA in detection of myocardial ischemia by using a model of exercise-stress induced transitory ischemia. Methods: The study included 43 consecutive patients with positive exercise stress test and coronary artery disease confirmed by coronary angiography (ischemic group) and 22 healthy volunteers with negative exercise stress test (control group). IMA plasma levels were measured before and at nine time points after exercise over a 6-hour period. Results: IMA kinetics was significantly different between the ischemic and control group (p = 0.03). In the ischemic group, IMA plasma levels peaked between the 3rd and 4th hour after exercise. However, due to large interindividual differences in the time-to-peak IMA values, a standard IMA kinetics curve could not be defined for the patients with transitory myocardial ischemia. On the other hand, with the cutoff value of a 10.6% relative increase, sensitivity and specificity of IIVIA for the detection of myocardial ischemia were sufficiently high at 81% and 82%, respectively. Conclusions: Although an optimum time for the detection of recent myocardial ischemia by a single IMA sampling could not be defined, serial measurements of IMA can be a useful biochemical tool for the detection of myocardial ischemia in patients with doubtful exercise stress test results.