Do cytokines enable risk stratification to be improved in NYHA functional class III patients? Comparison with other potential predictors of prognosis

Abstract

Aims: Elevated plasma levels of proinflammatory cytokines have been reported in patients with congestive heart failure. The purpose of this study was to assess whether cytokines improve risk stratification in a homogenous group of NYHA class III patients with a left ventricular ejection fraction <40%. Methods and Results: Plasma concentrations of big endothelin, tumour necrosis factor alpha, interleukins -1, -6, -10 and -12, sCD14 and GM-CSF were measured by ELISA in 91 NYHA III patients [mean (SD) age: 55 (10) years, 69% male, 34% coronary artery disease, 66% dilated cardiomyopathy] with a left ventricular ejection fraction and a peak oxygen uptake (peak VO2) of 19 (9)% and 12·1 (3·6) ml min -1.kg-1, respectively. During follow-up [22 (13) months], 31 patients (34%) died due to cardiovascular causes. In non-survivors, interleukin-6 was twice as high as in survivors [12·8 (16·9)pg.ml-1 vs 5·6(5·3)pg.ml-1, P<0.003], whereas plasma concentrations of the other cytokines showed no significant differences. Concerning long-term survival (≥ 1 year), multivariate Cox regression analysis revealed an independent prognostic power for interleukin-6, which was further improved by combining with left ventricular ejection fraction and peak VO2, while for short-term survival (up to 6 months) interleukin-6 did not allow risk stratification. Conclusion: In NYHA class III patients, plasma concentrations of interleukin-6 are predictive of long-term survival. However, its value may be limited for clinical decision-making for cardiac transplantation (short-term survival). © 2001 The European Society of Cardiology.