Abstract
Background A systemic proinflammatory state plays a central role in the development of heart failure with preserved ejection fraction. Low-level transcutaneous vagus nerve stimulation suppresses inflammation in humans. We conducted a sham-controlled, double-blind, randomized clinical trial to examine the effect of chronic low-level transcutaneous vagus nerve stimulation on cardiac function, exercise capacity, and inflammation in patients with heart failure with preserved ejection fraction. Methods and Results Patients with heart failure with preserved ejection fraction and at least 2 additional comorbidities (obesity, diabetes, hypertension, or age ≥65 years) were randomized to either active (tragus) or sham (earlobe) low-level transcutaneous vagus nerve stimulation (20 Hz, 1 mA below discomfort threshold), for 1 hour daily for 3 months. Echocardiography, 6-minute walk test, quality of life, and serum cytokines were assessed at baseline and 3 months. Fifty-two patients (mean age 70.4±9.2 years; 70% female) were included (active, n=26; sham, n=26). Baseline characteristics were balanced between the 2 arms. Adherence to the protocol of daily stimulation was >90% in both arms (P>0.05). While the early mitral inflow Doppler velocity to the early diastolic mitral annulus velocity ratio did not differ between groups, global longitudinal strain and tumor necrosis factor-α levels at 3 months were significantly improved in the active compared with the sham arm (-18.6%±2.5% versus -16.0%±2.4%, P=0.002; 8.9±2.8 pg/mL versus 11.3±2.9 pg/mL, P=0.007, respectively). The reduction in tumor necrosis factor-α levels correlated with global longitudinal strain improvement (r=-0.73, P=0.001). Quality of life was better in the active arm. No device-related side effects were observed. Conclusions Neuromodulation with low-level transcutaneous vagus nerve stimulation over 3 months resulted in a significant improvement in global longitudinal strain, inflammatory cytokines, and quality of life in patients with heart failure with preserved ejection fraction. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT03327649.