• To demonstrate a clinically significant reduction of office cuff systolic blood pressure at six months. [ Time Frame: 6 months ]
• To demonstrate a sustained response to therapy through 12 months. [ Time Frame: 12 months ]
• System and procedure related adverse event free rate in the first 30 days. [ Time Frame: 30 days ]
• Hypertension-related adverse event and serious device-related adverse event free rate more than 30 days post-implant to 13 months. [ Time Frame: 13 months ]
• Serious therapy-related adverse event free-rate through 6 months. [ Time Frame: 6 months ]

• To demonstrate a clinically significant reduction of office cuff systolic blood pressure at six months.
• To demonstrate a sustained response to therapy through 12 months.
• System and procedure related adverse event free rate in the first 30 days.
• Hypertension-related adverse event and serious device-related adverse event free rate more than 30 days post-implant to 13 months.
• Serious therapy-related adverse event free-rate through 6 months.

• To compare changes between the Rheos ON and Rheos OFF arms in antihypertensive therapeutic index (ATI) at six months. [ Time Frame: 6 months ]
• To demonstrate a clinically significant reduction of 24-hour ambulatory systolic BP at six months. [ Time Frame: 6 months ]
• To demonstrate a significant absolute reduction in systolic BP at six months, as measured by office cuff. [ Time Frame: 6 months ]
• To demonstrate a significant absolute reduction in 24-hour ambulatory systolic BP at six months. [ Time Frame: 6 months ]
• To further demonstrate sustained response to therapy by evaluating an immediate (randomized to ON) vs. deferred (randomized to OFF) therapy comparison of average absolute reduction in systolic BP as measured by office cuff at 12 months. [ Time Frame: 12 months ]

• To compare changes between the Rheos ON and Rheos OFF arms in antihypertensive therapeutic index (ATI) at six months.
• To demonstrate a clinically significant reduction of 24-hour ambulatory systolic BP at six months.
• To demonstrate a significant absolute reduction in systolic BP at six months, as measured by office cuff.
• To demonstrate a significant absolute reduction in 24-hour ambulatory systolic BP at six months.
• To further demonstrate sustained response to therapy by evaluating an immediate (randomized to ON) vs. deferred (randomized to OFF) therapy comparison of average absolute reduction in systolic BP as measured by office cuff at 12 months.

The purpose of this clinical trial is to demonstrate the efficacy and safety of the Rheos system in subjects with hypertension that are resistant to treatment with at least three anti-hypertension agents, one of which is a diuretic.

Inclusion Criteria:

• Be at least 21 years of age and no more than 80 years of age.
• Have been assessed with bilateral carotid bifurcations that are easily interrogated by carotid duplex ultrasound and are below the level of the mandible.
• Office cuff systolic blood pressure greater than or equal to 160 mmHg and have a diastolic blood pressure greater than or equal to 80 mmHg as well as a 24-hour ambulatory systolic blood pressure greater than or equal to 135 mmHg despite at lest one month of maximally tolerated therapy with at least three anti-hypertensive medications, of which at least one must be a diuretic.
• Must have completed the drug compliance questionnaire and have been judged to be compliant with medications.
• For subjects that have had prior bariatric surgery, they must be at least 1 year post-surgery and at a stable weight.
• If female, the subject must be surgically sterile, or using a medically accepted method of birth control and agree to continue use of this method for the duration of the trial. Women of childbearing potential must have a negative serum pregnancy test in the pre-implant blood evaluation.
• Must be an appropriate or reasonable surgical candidate.
• Have signed a CVRx approved informed consent form for participation in this study

Exclusion Criteria:

• Have known or suspected baroreflex failure or autonomic neuropathy.
• Have an arm circumference greater than 46 cm and/or body mass index of greater than 45.
• Have significant cardiac bradyarrhythmias.
• Have chronic atrial fibrillation.
• Have significant orthostatic hypotension
• Had a solid organ or hematologic transplant.
• Had a myocardial infarction, unstable angina, syncope, or cerebral vascular accident within the past 3 months.
• Have carotid atherosclerosis producing a 50% or greater reduction in linear diameter as determined by ultrasound or angiographic evaluation as determined within 6 months of enrollment in the trial.
• Have ulcerative plaques in the carotid artery as determined by ultrasound or angiographic evaluation.
• Have prior surgery, radiation, or endovascular stent placement in either carotid sinus region.

• Have severe chronic kidney disease as defined by:

  • Currently undergoing dialysis or dialysis is planned within 3 months of the implant date
  • eGFR of ≤30 ml/min/1.73m²
• Have hypertension secondary to an identifiable and treatable cause other than sleep apnea.
• Have clinically significant cardiac structural valvular disease.
• Have clinically significant reactive airway disease, chronic obstructive pulmonary disease, and/or primary pulmonary hypertension.
• Have an uncontrolled comorbid medical condition that would adversely affect participation in the trial.
• Have a clinically significant psychological illness that would prohibit the subject's ability to meet the protocol requirements
• Are currently taking an imidazolone receptor agonist
• Are unable or unwilling to fulfill the protocol medication compliance and follow-up requirements.
• Have an active infection within the last month.
• Have a co-morbid condition that reduces life expectancy to less than one year.
• Are enrolled in another concurrent clinical trial, without prior approval of CVRx.