Inhibition of the interleukin (IL)-1β innate immunity pathway is associated with anti-inflammatory effects and a reduced risk of recurrent cardiovascular events in stable patients with previous myocardial infarction (MI) and elevated high-sensitivity C-reactive protein (hs-CRP).

This study assessed the association between IL-1β level with all-cause mortality in patients with acute ST-segment elevation MI who underwent primary percutaneous coronary intervention and the interplay between IL-1β and hs-CRP concentrations on the risk of premature death.

IL-1β concentration was measured in 1,398 patients with ST-segment elevation MI who enrolled in a prospective cohort. Crude and hazard ratios for all-cause and cardiovascular mortality were analyzed at 90 days and 1 year using multivariate Cox proportional regression analysis. Major adverse cardiovascular events (MACEs) were analyzed.

IL-1β concentration measured at admission was associated with all-cause mortality at 90 days (adjusted hazard ratio [adjHR]: 1.47 per 1 SD increase; 95% confidence interval [CI]: 1.16 to 1.87; p < 0.002). The relation was nonlinear, and the highest tertile of IL-1β was associated with higher mortality rates at 90 days (adjHR: 2.78; 95% CI: 1.61 to 4.79; p = 0.0002) and at 1 year (adjHR: 1.93; 95% CI: 1.21 to 3.06; p = 0.005), regardless of the hs-CRP concentration. Significant relationships were equally observed when considering cardiovascular mortality and MACEs at 90 days (adjHR: 2.42; 95% CI: 1.36 to 4.28; p = 0.002, and adjHR: 2.29; 95% CI: 1.31 to 4.01; p = 0.004, respectively) and at 1 year (adjHR: 2.32; 95% CI: 1.36 to 3.97; p = 0.002, and adjHR: 2.35; 95% CI: 1.39 to 3.96; p = 0.001, respectively).

IL-1β measured at admission in patients with acute MI was independently associated with the risk of mortality and recurrent MACEs.