The value of plasma levels of tumor necrosis factor-alpha and interleukin-6 in predicting the severity and prognosis in patients with congestive heart failure.

Background: High plasma levels of pro-inflammatory cytokines play an important role in the pathophysiology of congestive heart failure (CHF). Therefore, we conducted a case-control study to determine the correlations between plasma levels of cytokines, i.e., tumor necrosis factor-alpha (TNF-alpha) and interleukin (IL)-6, and the severity and mortality in patients with CHF.
Methods: One-hundred and 18 cases (62+/-15 years old) were classified into 3 groups: group 1 comprised 44 control cases with normal coronary arteriogram and left ventriculography and without valvular disorders or cardiomyopathy; group 2 comprised of 37 cases with mild CHF in New York Heart Association (NYHA) functional class (FC) II; group 3 had 37 cases with moderate/severe CHF in NYHA FC III or IV. Pre-catheterization plasma levels of TNF-alpha and IL-6 along with clinical and hemodynamic variables and follow-up data of cardiac death were assessed.
Results: Patients of group 3 had smaller body mass index, lower systolic and diastolic blood pressures, faster heart rates, higher left ventricular end-diastolic pressure and lowered triglyceride levels than the patients of groups 1 and 2. The plasma levels of TNF-alpha and IL-6 increased significantly in patients of group 3 in comparison with patients of groups 1 and 2 (both p < 0.001). Over the following 1.5 years, 13 patients died. Univariate analysis identified the following variables to be associated with poor prognosis: NYHA FC (p < 0.001), plasma TNF-alpha (p = 0.013), plasma IL-6 (p < 0.001), systolic blood pressure (p = 0.001), heart rate (p = 0.045) and left ventricular end-diastolic pressure (p = 0.021). Multivariate Cox regression analysis identified the independent predictors of cardiac death as FC (p = 0.007) and plasma IL-6 (p = 0.021).
Conclusions: Our findings indicate that the plasma levels of IL-6 and TNF-alpha and especially the former, is a useful marker to correlate the progression of severity and late cardiac death in patients with CHF.