Vagus Nerve Stimulation Provides Multiyear Improvements in Autonomic Function and Cardiac Electrical Stability in the ANTHEM-HF Study

BackgroundPatients with heart failure reduced left ventricular ejection fraction (LVEF) (HFrEF) experience long-term deterioration of autonomic function and cardiac electrical stability linked to increased mortality risk. The Autonomic Neural Regulation Therapy Enhance Myocardial Function in Heart Failure (ANTHEM-HF) trial reported improved rate variability (HRV) turbulence (HRT) T-wave alternans (TWA) after 12 months vagus nerve stimulation (VNS). We investigated whether the benefits chronic VNS persist long term.Methods ResultsEffects on rate, HRV, HRT, TWA, R-wave heterogeneity (RWH, TWH), nonsustained tachycardia (NSVT) incidence were evaluated all ANTHEM-HF patients ambulatory ECG data at 24 36 (n = 25). markers significantly compared baseline [heart square root mean squared differences successive normal-to-normal intervals (rMSSD), standard deviation (SDNN), HF-HRV, HRT slope, P < 0.05]. Peak TWA levels remained (P 0.0001). Reductions RWH TWH 6 persisted 0.01). NSVT decreased 12, 24, 0.025). No sudden deaths, fibrillation, or sustained occurred.ConclusionIn symptomatic HFrEF, appears confer wide-ranging, persistent improvements tone (HRV), baroreceptor sensitivity (HRT), (TWA, RWH, TWH).