Inflammatory cytokines provide limited early prognostic information in emergency department patients with suspected myocardial ischemia

Abstract

Study objective The aim of this study was to assess the early prognostic value of the inflammatory cytokines interleukin 6, interleukin 8, and tumor necrosis factor α in a cohort of emergency department (ED) patients with chest pain who have suspected myocardial ischemia. Methods One hundred eighteen patients with chest pain presenting to 2 urban EDs were studied. Interleukin 6, interleukin 8, and tumor necrosis factor α levels were assayed at presentation. The end point was the occurrence of a serious cardiac event (death, nonfatal acute myocardial infarction, myocardial revascularization, or readmission with an acute coronary syndrome) during the index admission or subsequent 3 months. Results Mean levels of all 3 cytokines were higher among patients experiencing a serious cardiac event, with the greatest differences observed in levels of interleukin 6 (mean 2.5 pg/mL [95% confidence interval (CI) 1.2 to 3.7 pg/mL] versus mean 9.8 pg/mL [95% CI 2.4 to 17.2 pg/mL]). Interleukin 6 had a sensitivity of 35% (95% CI 20% to 54%), a specificity of 86% (95% CI 76% to 92%), and an overall prognostic accuracy of 71% (95% CI 63% to 79%) for predicting serious cardiac events. However, logistic regression analysis revealed that the only independent predictor of an adverse outcome was an ECG suggestive of ischemia at presentation. Conclusion Among patients presenting to the ED with suspected myocardial ischemia, higher levels of inflammatory cytokines are associated with an increased risk of a serious cardiac event during the subsequent 3 months. There is, however, considerable overlap in levels among patients who do and do not have a serious cardiac event, limiting their utility as predictors of outcome in individual patients.