Adverse Outcomes Associated With Interleukin-6 in Patients Recently Hospitalized for Heart Failure With Preserved...

Inflammation may play a role in the pathophysiology of heart failure with preserved ejection fraction. We examined whether circulating levels of interleukin-6 identify patients at greater risk of adverse outcomes following hospitalization with heart failure with preserved ejection fraction.

We assessed relationships between interleukin-6 (IL-6) tertiles (T1-3) and all-cause death, cardiovascular death, and subsequent heart failure hospitalization (sHFH) in 286 patients recently hospitalized with heart failure with preserved ejection fraction. Associations between IL (interleukin)-6 and outcomes were examined in a Cox-regression model adjusted for risk factors including BNP (B-type natriuretic peptide). Biomarkers including hsCRP (high-sensitivity C-reactive protein) were assessed.

The range of IL-6 (pg/mL) in each tertile was T1 (0.71-4.16), T2 (4.20-7.84), and T3 (7.9-236.32). Compared with T1, patients in the highest IL-6 tertile were more commonly male (56% versus 35%) and had higher creatinine (117±45 versus 101±36 μmol/L), hsCRP (11.6 [4.9-26.6]mg/L versus 2.3[1.1-4.2] mg/L). In univariable analysis, rates of all-cause death, cardiovascular death, and sHFH were higher in T3 versus T1. All-cause and cardiovascular death rates remained higher in T3 versus T1 after adjustment (P<0.001). One log unit increase in IL-6 was associated with higher risk of all-cause death (hazard ratio, 1.46 [1.17-1.81]), cardiovascular death (hazard ratio, 1.40 [1.10-1.77]), and sHFH (hazard ratio, 1.24 [1.01-1.51]) after adjustment. One log unit increase in hsCRP was associated with a higher risk of cardiovascular death and all-cause death before and after adjustment for other factors but was not associated with risk of sHFH before or after adjustment.

In patients recently hospitalized with heart failure with preserved ejection fraction, IL-6 is an independent predictor of all-cause mortality, cardiovascular death, and sHFH after adjustment for risk factors including BNP. These findings are of particular relevance in the context of current anti-IL-6 drug development.