Interleukin-18/interleukin-10 ratio is an independent predictor of recurrent coronary events during a 1-year follow-up in patients with acute coronary syndrome

Background: The pro-inflammatory cytokine IL-18 has been suggested to play a role in atherogenesis and atheromatous plaque rupture leading to the acute coronary syndrome (ACS). Conversely, the anti-inflammatory cytokine IL-10 seems to have an atheroprotective role. Patients with unstable coronary artery disease show an imbalance between serum levels of pro- and anti-inflammatory cytokines, and studies have shown that IL-18/IL-10 ratio is an independent predictor of adverse in-hospital events in patients with ACS. We assessed the long-term prognostic significance of admission interleukin-18 (IL-18)/interleukin-10 (IL-10) ratio for recurrent coronary events during a 1-year follow-up in patients presenting with an ACS. Methods: We assessed independent predictors of the combined end-point using multiple logistic regression analysis, in 186 patients (138 men, 65 12 years) with ACS (75 STEMI, 65 NSTEMI and 46 unstable angina). The composite of cardiac death and re-hospitalization with non-fatal myocardial infarction, or unstable angina, was the pre-specified study end-point. Serum IL-10 and IL-18 levels were measured at study entry using commercially available ELISAs. Results: During the 1-year follow-up, 48 (26%) patients had recurrent cardiac events and 138 (74%) were event-free. IL-18/IL-10 ratio predicted the occurrence of adverse cardiac events (OR 1.91, 95% CI 1.37-2.65, p < 0.001), and was found to be an independent predictor among other established biochemical and clinical risk markers (OR 2.31, 95% CI 1.55-3.42, p < 0.001). Conclusions: Serum IL-18/IL-10 ratio is an independent predictor of recurrent coronary events during long-term follow-up in patients presenting with ACS. Our study further supports the hypothesis that the balance between pro-inflammatory and anti-inflammatory cytokines may be an important determinant of patient outcome, suggesting a pathogenic role in plaque progression and instability. (c) 2006 Elsevier Ireland Ltd. All rights reserved.