ANTHEM-HFrEF Pivotal Study

Inclusion Criteria: 1. Age 18 or above 2. Willing and capable of providing informed consent 3. Capable of participating in all testing associated with this clinical investigation 4. Stable, guideline-directed medical therapy for at least 4 weeks before subject screening. Unrestricted changes in diuretics are allowed during the 4 weeks, as long as the subject remains on a diuretic. If the use of an ARNI is being contemplated for a study subject, ARNI should be administered, and GDMT optimized, before the subject is randomized. No more than a 100% increase or 50% decrease of the dosage of any medication other than a diuretic is permitted. For these medications, medication changes within a class are allowed, as long as the equivalent dosage is within these specified limits 5. Stable symptomatic heart failure NYHA class III; or NYHA class II with a heart failure hospitalization in the previous 12 months. HF hospitalization may include an overnight hospital or hospital-based observation unit stay with a primary diagnosis of HF, or an emergency department visit with a primary diagnosis of HF, and will in either case include documentation of intravenous HF therapy administration or other intervention for HF 6. Left ventricular ejection fraction (EF) ≤ 35% and left ventricular end-diastolic diameter (LVEDD) \< 8.0 cm, as confirmed by the core echocardiography laboratory during screening 7. N-terminal pro-BNP (NT-proBNP) level of at least 800 pg/mL, as determined by the core laboratory; or NT-proBNP level of at least 1200 pg/mL, as determined by the core laboratory, for patients with permanent atrial fibrillation or reporting signs or symptoms of atrial fibrillation at the time that the NT-proBNP sample is drawn 8. Received a standard cardiac assessment, including history, physical exam, and electrocardiogram, and determined by a heart failure cardiologist and study surgeon to be an appropriate candidate for the study's surgical procedure 9. Physically capable and willing to perform repeated 6-minute walk tests associated with the study, and having a baseline distance of between 150 and 450 meters. Symptoms limiting the duration of the 6 minute walk test must be due primarily to heart failure Exclusion Criteria: 1. Refractory symptomatic hypotension (systolic blood pressure below 80 mmHg) 2. Complete AV block treated with unipolar pacemaker therapy 3. Currently implanted vagus nerve stimulation (VNS) device, baroreceptor activation therapy (BAT) device, other nerve stimulator, artificial or donor heart, or ventricular assist device (VAD) 4. Heart failure of non-ischemic origin for less than 6 months, or due to congenital heart disease, hypertrophic obstructive cardiomyopathy, or infiltrative cardiomyopathy (e.g. amyloidosis, sarcoidosis) 5. Moderate (3+) or severe (4+) aortic valve or mitral valve stenosis; moderate (3+) or severe (4+) aortic valve insufficiency; or severe (4+) mitral valve insufficiency 6. Symptomatic uncontrolled bradycardia 7. On renal dialysis 8. Involvement in any concurrent clinical study with an investigational therapy