Ischemia Modified Albumin for the assessment of patients presenting to the emergency department with acute chest pain but normal or non-diagnostic 12-lead electrocardiograms and negative cardiac troponin T

Background: The diagnosis of myocardial ischemia in patients with acute chest pain at rest but non-diagnostic electrocardiograms (ECG) is problematic. Ischemia Modified Albumin (IMA(R)) is a new biochemical marker of ischemia, which may be useful to characterise acute coronary syndrome (ACS) patients. Methods: We studied 131 patients (mean age 58.5 years; 95 mate) presenting to the emergency department with symptoms suggestive of ACS but with normal or non-diagnostic ECGs. Cardiac troponin T (cTnT) and IMA were measured within 3 h of last chest pain episode. Based on hospital diagnostic test results, patients were classified as having ACS or non-ischemic chest pain (NICP), by two independent cardiologists unaware of IMA results. Results: Mean IMA levels (U/ml) were higher in patients with ACS (98.3 +/- 11) compared to patients with NICP (85.5 +/- 15); p < 0.0001. IMA levels > 93.5 U/ml demonstrated a sensitivity and specificity of 75% for the diagnosis of ACS; area under the receiver operator characteristic curve 0.78 (95% CI: 0.70-0.85). If we applied the manufacturer cutoff point of 85 U/ml, the sensitivity of IMA increased to 90.6% with a specificity of 49.3% (negative predictive value = 84.6%). In combination with cTnT (6-12 h) ( > 0.05 ng/ml), the sensitivity increased to 92.2%. After multivariate analysis, IMA levels > 85 U/ml (odds ratio = 14.6 [95% CI 4.4-48.4]; p < 0.0001), age and prior myocardial infarction were independent predictors of ACS. Conclusion: IMA may be a useful biomarker for the identification of ACS in patients presenting with typical acute chest pain but normal or non-diagnostic ECGs. (C) 2004 Elsevier Ireland Ltd. All rights reserved.