Interleukin-6 and tumor necrosis factor-alpha as biochemical markers of heart failure: a head-to-head clinical comparison with B-type natriuretic peptide.

BACKGROUND: The reliability of interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) as biochemical markers of heart failure in comparison to B-type natriuretic peptide (BNP) has not been investigated in depth. AIM: To compare the correlations between IL-6, TNF, BNP plasma concentrations and some clinical and instrumental variables and their prognostic value in heart failure patients. METHODS: In 79 patients with heart failure, the correlations between IL-6, TNF and BNP plasma concentrations and a series of 18 variables were studied. Outcome events were death from any cause and combined death and heart transplantation. RESULTS: At univariate analysis, BNP and IL-6 plasma concentrations correlated with each other (r = 0.4828; P < 0.0001), with New York Heart Association class, fluid retention, left ventricular ejection fraction, mean right atrial pressure, mean pulmonary pressure and cardiac index. All these correlations were stronger with BNP. TNF plasma concentration correlated only with New York Heart Association class and left ventricular ejection fraction.During follow-up, 1-32 months, 14 patients died and nine underwent heart transplantation. At univariate analysis, both BNP and IL-6 plasma concentrations were predictors of death and heart transplantation, but only BNP was a predictor of death; however, only creatinine plasma level was an independent predictor of prognosis. CONCLUSION: IL-6 and TNF are less reliable biochemical markers than BNP in heart failure patients.