Central Pressure Variability After Low-Level Tragus Stimulation in Acute Decompensated Heart Failure.

BACKGROUND

Increased variability in central aortic systolic pressure (CASP) and pulse pressure (PP) are predictors of poor cardiovascular disease outcomes. Low-level tragus stimulation (LLTS) is a noninvasive method to reduce sympathetic tone via vagal afferent fibers. It is unknown if LLTS has a favorable effect on elevated variability in CASP and PP in patients with acute decompensated heart failure (HF) (ADHF).

METHODS

Patients hospitalized for ADHF after initial stabilization (median 80 years, males 60%) were randomly assigned to active or sham group, and LLTS (20 Hz, 1 mA) was delivered using an ear clip attached to the tragus (active group) or the earlobe (sham group) for 1 hour daily over 5 days. The variability of PP and CASP was measured before and after each stimulation.

RESULTS

Each of SD, CV, and δ in PP, CASP, radial augmentation index (rAI), %PP variation (PPV), and PP × heart rate (HR) was significantly decreased after stimulation in the active group (n = 8) (all P < 0.05), while δ in CASP was significantly increased after stimulation in the sham group (n = 8) (P < 0.05). All the changes in SD, CV, and δ in PP, CASP, rAI, %PPV, and PP × HR before and after stimulation were also significantly different between active and sham groups (all P < 0.05).

CONCLUSIONS

In this proof-of-concept study, LLTS led to a better hemodynamic profile, as evident in variability reduction in PP, CASP, and rAI. Further studies are warranted to study the long-term hemodynamic effects of LLTS on HF.Clinical trial registration: UMIN000044121.