Advances in Our Clinical Understanding of Autonomic Regulation Therapy Using Vagal Nerve Stimulation in Patients Living With Heart Failure.

The ANTHEM-HF, INOVATE-HF, and NECTAR-HF clinical studies of autonomic regulation therapy (ART) using vagus nerve stimulation (VNS) systems have collectively provided dose-ranging information enabling the development of several working hypotheses on how stimulation frequency can be utilized during VNS for tolerability and improving cardiovascular outcomes in patients living with heart failure (HF) and reduced ejection fraction (HFrEF). Changes in heart rate dynamics, comprising reduced heart rate (HR) and increased HR variability, are a biomarker of autonomic nerve system engagement and cardiac control, and appear to be sensitive to VNS that is delivered using a stimulation frequency that is similar to the natural operating frequency of the vagus nerve. Among prior studies, the ANTHEM-HF Pilot Study has provided the clearest evidence of autonomic engagement with VNS that was delivered using a stimulation frequency that was within the operating range of the vagus nerve.

Therapeutic responsiveness to vagus nerve stimulation in patients receiving beta-blockade for heart failure with reduced ejection fraction.

Background: The effect of beta-blockade (BB) on response to vagus nerve stimulation (VNS) has not been reported in patients with heart failure and reduced ejection fraction (HFrEF). In the ANTHEM-HF Study, 60 patients received chronic cervical VNS. Background pharmacological therapy remained unchanged during the study, and VNS intensity was stable once up-titrated.

Comparison of symptomatic and functional responses to vagus nerve stimulation in ANTHEM-HF, INOVATE-HF, and NECTAR-HF.

Aims: Clinical studies of vagal nerve stimulation (VNS) for heart failure with reduced ejection fraction have had mixed results to date. We sought to compare VNS delivery and associated changes in symptoms and function in autonomic regulation therapy via left or right cervical vagus nerve stimulation in patients with chronic heart failure (ANTHEM-HF), increase of vagal tone in heart failure (INOVATE-HF), and neural cardiac therapy for heart failure (NECTAR-HF) for hypothesis generation.

Methods And Results: Descriptive statistics were used to analyse data from the public domain for differences in proportions using Pearson's chi-square test, differences in mean values using Student's unpaired t-test, and differences in changes of mean values using two-sample t-tests.

Background pharmacological therapy in the ANTHEM-HF: comparison to contemporary trials of novel heart failure therapies.

Aims: Clinical trials of new heart failure (HF) therapies administer guideline-directed medical therapy (GDMT) as background pharmacologic treatment (BPT). In the ANTHEM-HF Pilot Study, addition of autonomic regulation therapy to GDMT significantly improved left ventricular function, New York Heart Association (NYHA) class, 6 min walk distance, and quality of life in patients with HF with reduced ejection fraction (HFrEF). A post hoc analysis was performed to compare BPT in ANTHEM-HF with two other trials of novel HF therapies: the PARADIGM-HF study of sacubitril-valsartan and the SHIFT study of ivadrabine.

Impact of chronic kidney disease and anemia on hospitalization expense in patients with left ventricular dysfunction.

To estimate the independent effects of kidney disease, anemia, and the treatment effects of angiotensin-converting enzyme (ACE) inhibitors on hospitalization cost in patients with heart failure, we used data from the prevention and treatment trials of the Studies of Left Ventricular Dysfunction trial and retrospectively estimated the relative effects of decreased kidney function, as measured by estimated glomerular filtration rate (GFR) at enrollment, and anemia, as measured by hematocrit levels at enrollment, on hospital utilization and expense. Independent of the effects of age, gender, New York Heart Association (NYHA) class, ejection fraction, and the presence of diabetes mellitus, GFR was significantly related to hospitalization expense (percent change in hospitalization expense -16.8%, 95% confidence interval [CI] -11.