Interleukin-1 receptor antagonist levels correlate with extent of myocardial loss in patients with acute myocardial infarction

Background: Interleukin-1 receptor antagonist (IL-1Ra) levels are elevated early in patients with acute myocardial infarction (MI) and often precede release of markers of necrosis; however, IL-1Ra levels did not correlate previously with infarct size and prognosis in such patients. Hypothesis: The goal of our study was to evaluate prospectively the correlation between IL-1Ra levels upon emergency department (ED) presentation and the extent of myocardial necrosis and prognosis in patients with ST-segment elevation MI. Methods: Levels of IL-1Ra were measured upon ED presentation in 44 consecutive patients (40 men, aged 55 ± 10 years). Peak values of creatine kinase (CK) and CK-MB were determined during hospitalization, and left ventricular ejection fraction (LVEF) was evaluated by echocardiography before discharge. All patients were followed prospectively and underwent clinical and echocardiographic assessment at 42 ± 3 months after the infarction. Results: Levels of IL-1Ra upon ED presentation correlated directly with CK (p = 0.002) and CK-MB (p = 0.01) peak levels and correlated inversely with LVEF before discharge (p = 0.009). Patients with in-hospital adverse events had significantly higher IL-1Ra levels upon ED admission (n = 10, 2620 ± 4706 pg/ml) than those without events (n = 34, 598 ± 457 pg/ml)(p = 0.015). Conclusions: In patients with MI, levels of IL-1Ra upon ED presentation correlated significantly with the extent of myocardial necrosis, as measured by cardiac enzymes peak and reduction of LVEF, and are predictive of in-hospital events. Results of this study may influence early therapeutic approach in patients with acute MI.