Clinical outcome of electrical transcutaneous auricular vagal stimulation in patients with stable symptomatic chronic heart failure - A pilot study

INTRODUCTION AND AIM OF STUDY: Chronic heart failure (CHF) is characterized by an autonomic imbalance of vagal activity and increased sympathetic activity. Low-level transcutaneous auricular vagus nerve stimulation (Ta-VNS) may be a safe complementary treatment option for CHF patients. METHODS: In this randomized clinical trial, a total of 13 patients with diagnosed CHF and reduced ejection fraction were randomized to receive either low-level Ta-VNS with electrodes applied in the triangular fossa of the ear (amplitude 1 mA, frequency 1 Hz for 40 min, followed by a 20-minute break) or sham intervention. The primary endpoint was an increase of 6-minutes walking distance assessed during cardiological screening and closing visits. Secondary endpoints included assessment of New York heart association (NYHA)-classification, a physical examination, electrocardiogram and blood sampling for n-terminal pro-brain natriuretic peptide (NT-proBNP)and C-reactive protein (CRP). Echocardiogram was performed at screening and adverse events were assessed at the closing visit. RESULTS: A total of 12 patients completed the trial. 6-minute-walking-distance increased by 101.1 (94.6) metres in the transcutaneous auricular vagal nerve stimulation group, and by 7.2 (41.8) metres in the sham intervention group (p = 0.04). Concerning the secondary outcome parameters, including CRP and NT-proBNP, no difference was observed between groups. No adverse events were observed. CONCLUSION: In patients with CHF, Ta-VNS effectively improved 6-minutes walking distance while no such effect was observed in the sham intervention group. Further investigation of this finding in a larger patient collective might be of interest.