Interleukin-6
myocardial salvage, infarct, myocardial injury
INFARCT
Elevated IL-6 has been demonstrated in ischaemic myocardium in rat models,We observed a significant correlation between IL-6 and TnT levels in both the tocilizumab and placebo group. In the group presenting ≤3 hours from symptom onset, IL-6 was associated with higher TnT levels, larger infarct sizes and less myocardial salvage in the placebo group. These associations were markedly attenuated in the tocilizumab group, suggesting that IL-6 may be an important therapeutic target in STEMI patients. This parallels findings with regard to procedure-related myocardial injury in NSTEMI.Interleukin-6 had a more pronounced increase in patients treated with tocilizumab presenting >3 hours from symptom onset that also correlated with lower MSI. This does not necessarily imply a negative effect of tocilizumab, but may reflect that upstream mediators of IL-6 release have already been activated. The further increase in IL-6 after the administration of tocilizumab occurs in a setting where IL-6 is uncoupled from its downstream effect. Indeed, patients presenting >3 hours from symptom onset in the ASSAIL-MI study had better effect of tocilizumab on MSI despite the reported increase in IL-6.