Chronic heart failure as a metabolic disorder

Congestive chronic heart failure (CHF) is a progressive disorder in which a complex interaction of haemodynamic, neurohormonal and metabolic disturbances leads to subsequent immune activation. The greatest attention has been given to the concept that the progression of heart failure is due to neurohormonal abnormalities and this has led to substantial therapeutic benefits for CHF. The aim of this review is to describe a number of the interactions between neurohormonal pathways and metabolic problems relevant in CHF. Besides the renin-angiotensin-aldosterone-system, steroid and thyroid hormones, growth factors, insulin and inflammatory cytokines (e.g. tumour necrosis factor-alpha TNF-alpha]) are considered. TNF-alpha is potentially a key molecule with enormous interactive opportunities within a regulatory network of energy metabolism, immune function and neuroendocrine and hormonal function. The most dramatic metabolic problem in heart failure patients is the development of cardiac cachexia. Currently, no specific therapy exists and the prognosis is poor. There are promising approaches (counteracting TNF-alpha or applying anabolic growth factors) but these are not without risk and are expensive, and their application may, therefore, be limited to certain subgroups of patients. In the future, it will not be enough to monitor cardiac function and symptomatic status in heart failure patients. Rather, the patients' metabolic status may need to be taken, as well as an assessment of peak oxygen consumption, body composition and hormonal status.