Prognostic value of plasma interleukin-6 concentrations and the −174 G > C and −572 G > C promoter polymorphisms of the interleukin-6 gene in patients with acute myocardial infarction treated with thrombolysis

The present study was performed to investigate the prognostic value of plasma interleukin-6 (IL-6) concentrations and promoter polymorphisms of the IL-6 gene in patients with acute myocardial infarction treated with thrombolysis. Two hundred and eight patients with myocardial infarction treated with thrombolysis were included and followed for 2–5 years. Plasma concentrations of IL-6 were measured at admission and 48 h after admission. Genotyping for the −174 G>C and −572 G>C IL-6 polymorphisms was performed. Patients who died of cardiovascular causes or suffered a new myocardial infarction during follow-up had increased plasma concentrations of IL-6 at admission (P<0.002) and at 48 h after admission (P<0.05) compared with patients who had an uneventful course. IL-6 levels above the median at admission were independently associated with a worse prognosis. No associations were found between IL-6 levels and the promoter polymorphisms. The −174 G>C polymorphism was not associated with cardiovascular death or a new myocardial infarction, whereas the −572 G>C polymorphism showed a borderline significant increase in risk (P=0.05) in univariate analysis. In conclusion, the early IL-6 response during myocardial infarction is associated with prognosis in patients with Q-wave myocardial infarction, whereas no associations were found between IL-6 genotype and phenotype.