Low Level Tragus Stimulation in Acute Decompensated Heart Failure

Acute Decompensated Heart Failure (ADHF) is a major cause of morbidity and mortality. It is associated with increased systemic inflammation and poor outcomes.

Previous studies have demonstrated increased inflammation in patients with heart failure (HF). Increased activity of sympathetic nervous system in ADHF is linked to inflammation. Previous anti-inflammatory drug therapies in HF have demonstrated no significant impact on cardiovascular outcomes.

Low-level vagus nerve stimulation via stimulation of teh Tragus (LLTS) is a non-invasive way to modulate autonomic tone and thereby inflammation. Vagal nerve stimulation is thought to increase the parasympathetic activity and suppress the sympathetic activity. Recent experimental and clinical data suggest that low level tragus nerve stimulation (LLTS) may produce the same desired neuromodulator effect compared to LLVNS.

It is however unknown if LLTS in ADHF will directly lead to sympathetic tone reduction and increase in parasympathetic tone, or neuromodulation and lead to reduction in the levels of pro-inflammatory cytokines (CRP, IL-1, IL-6 and TNF-α) and an increase in the level of anti-inflammatory marker IL-10.

Autonomic tone could be assessed using heart rate variability. The objective of this proposal is to determine the impact of LLTS on inflammatory cytokines and HRV in patients with ADHF.

Patients will be randomized to either active or sham stimulation (2 hours daily).

Serum collected will (post admission and discharge day) will be used for cytokine and biomarker measurement. We will also measure 10-15 minute ECG to assess HRV. Dyspnea will be determined using patient assessment tool(visual analog scale).This investigation will likely establish the first evidence of effects of LLTS on suppression of inflammation and improvement in dyspnea scale, renal function and HRV in patients presenting with ADHF.

Inclusion criteria

Patients admitted with ADHF

Exclusion criteria

• Refusal to consent
• Complex congenital heart disease (Tetralogy of Fallot patients, single ventricle physiology)
• Recurrent vaso-vagal syncopal episodes
• Unilateral or bilateral vagotomy
• Sick sinus syndrome
• 2nd or 3rd degree AV block
• bifascicular block or prolonged 1st degree AV block (PR>300ms)
• Pregnant patients
• Prisoners
• Advanced renal dysfunction(defined as eGFR < 30, stage 4 or 5 chronic kidney disease)
• Hepatitis C or HIV
• Acute Myocardial infarction