Abstract 1793: Ischemia Modified Albumin Adds Sensitivity to the Initial Workup of Patients with Acute Chest Pain
Introduction: Ischemia modified albumin (IMA) may be an early sensitive biomarker of myocardial ischemia. We tested if IMA can predict in-hospital non-ST-elevation myocardial infarction (NSTEMI) and 30 day adverse cardiac events for patients with acute chest pain.
Hypothesis: We hypothesized that IMA would be more sensitive than initial troponin I to predict NSTEMI, and would also improve prediction of 30-day adverse cardiac events.
Methods: We prospectively recruited consecutive Emergency Department patients with acute chest pain at 2 university hospitals during a 3-month period (June-August 2006). Patients with STEMI were excluded. Serum was drawn at the bedside during the initial chest pain evaluation. Troponin I (Bayer Healthcare, Cambridge, MA) and IMA (ELISA: Inverness Medical, Louisville, USA) were independently analyzed. In-hospital NSTEMI was defined using ESC-ACC criteria. Adverse cardiac events were defined as MI, revascularization or death at follow-up. We calculated sensitivity, odds ratios (OR) and 95% confidence intervals (CI). We estimated the need to enroll 169 patients to detect a 15% improvement in sensitivity for NSTEMI using the IMA cutoff of 75 units/ml.
Results: 170 patients were enrolled (58% male, mean age 59±15, mean IMA 86±30 units/ml), of whom 16 (9.8%) developed NSTEMI during index hospitalization. Of 149 patients with 30-day follow-up, 27 (18.1%) had adverse cardiac events (16 MI, 13 revascularized, 2 died). The sensitivities of IMA and initial troponin I to detect NSTEMI and predict 30-day adverse events are summarized in the Table⇓.
Conclusions: In this analysis of Emergency Department patients with chest pain but without STEMI, IMA was more sensitive than initial troponin I to predict NSTEMI and sensitivity incrementally increased using a combination of both biomarkers. Combining IMA with traditional cardiac biomarkers may add incremental value to the initial evaluation of patients with acute chest pain.