Ischemia-modified albumin is a highly sensitive serum marker of transient myocardial ischemia induced by coronary vasospasm

Abstract

Ischemia-modified albumin, a new marker of myocardial ischemia, is known to elevate during ischemia induced by percutaneous coronary intervention. It is, however, not known whether ischemia-modified albumin also elevates during transient coronary vasospasm. We evaluated ischemia-modified albumin in patients undergoing intracoronary ergonovine spasm provocation test (n=26). For additional comparison, ischemia-modified albumin was also evaluated in elective percutaneous coronary intervention patients (n=18) and in patients with normal coronary angiography (n=10). Blood samples were taken from the arterial sheath before the procedure, just after procedural completion, or balloon inflation. Median ischemia-modified albumin level elevated significantly in patients with positive provocation test compared with baseline [n=16, 106.0 (interquartile range 96.5, 115.5) versus 128.5 (114.8, 171.8) U/ml, P<0.001], whereas it did not change in patients with negative provocation test [n=10, 109.5 (103.3, 115.0) versus 113.5 (104.0, 118.3) U/ml, P=0.108]. Ischemia-modified albumin was also higher after percutaneous coronary intervention [113.5 (101.0, 131.5) versus 151.0 (129.3, 231.0) U/ml, P<0.0001] and did not change in patients with normal coronary angiography [108.5 (99.3, 114.0) versus 110.0 (108.0, 114.0) U/ml, P=0.085]. Ischemia-modified albumin elevation higher than 9 U/ml after provocation test could detect the presence of coronary vasospasm, with an area under the receiver operating characteristic curve of 0.975 (95% confidence interval 0.921-1.000), with a sensitivity of 94% and a specificity of 99%. Serum albumin levels were within reference range for all patients and there was no significant relationship between albumin and baseline ischemia-modified albumin or postischemic ischemia-modified albumin. Thus, ischemia-modified albumin may have a role as a biochemical marker for transient myocardial ischemia induced by coronary vasospasm.