Serum catalytic iron as a novel biomarker of vascular injury in acute coronary syndromes

AIMS: Catalytic iron is associated with high oxidative stress during vascular injury. We measured catalytic iron in patients with suspected acute coronary syndromes (ACS) and healthy volunteers to evaluate its utility in early detection of patients with acute myocardial infarction (MI) and predicting major adverse cardiac events (MACE). METHODS AND RESULTS: Catalytic iron was measured on admission and 24 hours later in 127 patients with acute MI, 51 patients with suspected ACS without MI, and 250 healthy volunteers. Descriptive and decision statistics were performed for catalytic iron and troponin I. Catalytic iron levels at presentation were 1.5+2.0 micromol/l, 0.2+0.16 micromol/l, and 0.1+0.06 micromol/l for acute MI, suspected ACS without MI, and normals, respectively p<0.0001. Catalytic iron was elevated in all patients with MI at presentation. At a cutpoint of 0.30 micromol/L, the sensitivity, specificity, and diagnostic accuracy for identifying MI was 84%, 95%, and 92%, respectively. Increase in catalytic iron at 24 hours compared to baseline was associated with MACE at 30 days. CONCLUSIONS: Catalytic iron identified all patients with acute MI at presentation and serial elevation was independently associated with MACE. This biomarker of vascular injury is useful in the rapid serologic assessment of patients with suspected ACS.