Cardiac sympathetic innervation assessed by I123MIBG Imaging in different settings of patients affected by heart failure with reduced ejection fraction.

Heart failure (HF) is a leading cause of morbidity and mortality worldwide and has a relevant impact on socio-economic health aspects. An insufficient cardiac function leads to the activation of several compensatory mechanism that simultaneously act in order to compensate the effects of a failing heart. These mechanisms mainly consist in neuro-hormonal activation, enhanced sympathetic nervous system activity and natriuretic peptides synthesis and release. Imaging with MIBG, an analogue of norepinephrine, depicts the status of cardiac innervation in patients with HF and has been shown to yield prognostic information, with the potential to stratify patients for fatal and non-fatal cardiac events more accurately than traditional risk markers. Sympathetic nervous system hyperactivation play a detrimental role in the advancement of cardiac dysfunction and it is strictly related to several metabolic mechanisms that additionally influence prognosis. The identification of the pathophysiological pathway that relates adrenergic impairment with metabolic disorders might help in the identification of new therapeutic targets to improve HF survival and quality of life. Aim of the present research path was to evaluate sympathetic nervous system at myocardial level in different settings of patients affected by HF-REF by the use of I123MIBG cardiac scintigraphic study. In particular, in the current report we present the results of cardiac sympathetic activity evaluation in 3 specific groups of HF-REF patients, as diabetic HF patients, non-diabetic HF patients affected by insulin resistance and HF-REF patients also affected by sleep-disordered breathing.