Change in ischemia-modified albumin and its clinical significance during exercise stress testing

Background: There is little data about the additive effects of ischemia-modified albumin (IMA) on the exercise stress test (EST) used for the screening of ischemic heart disease. The relationship between myocardial ischemic burden and the change in IMA (ΔIMA) during EST was investigated. Methods and Results: EST was performed using the Bruce protocol to evaluate chest pain or exertional dyspnea in 155 patients (men 89, 53±13 years). Blood samples for IMA were obtained before and immediately after EST. According to the EST results and the pattern of ΔIMA, patients were categorized into 3 groups (none was classified as EST(-)/ΔIMA(+)): (1) (EST(-); (2) EST(+)/ΔIMA(-); and (3) EST(+)/ΔIMA(+). After EST, 60 of 155 (38.7%) patients were EST(+) and 14/60 (23.3%) were EST(+)/ΔIMA(+). Duke treadmill score was significantly lower in the EST(+)/ΔIMA(+) group compared with the other groups (-9.0±7.9, -1.7±4.2, 6.7±4.4, respectively, P<0.001); 43/60 (72%) patients with EST(+) underwent coronary angiography and the proportion of patients with a large ischemic burden was higher in the EST(+)/ΔIMA(+)group compared with the EST(+)/ΔIMA(-) group (72.7% vs 15.6%, P=0.001). Conclusions: Increased IMA after EST suggests a large ischemic burden in coronary artery disease, so the ΔIMA during EST may be useful for predicting the severity of myocardial ischemia.