The remedē System is an implantable device that treats central sleep apnea by electrically stimulating the phrenic nerve, the nerve that controls the diaphragm, to restore a more natural breathing pattern during sleep. Approved by the FDA in 2017, it is the first and only device of its kind, designed specifically for people whose brain intermittently fails to signal the body to breathe, a problem distinct from the far more common obstructive sleep apnea. In clinical trials, roughly six out of ten patients achieved at least a 50 percent reduction in breathing disruptions within six months, with benefits holding steady or improving through years of follow-up.
How the Remedē System Works
Central sleep apnea happens when the brain’s respiratory control center temporarily stops sending signals to the breathing muscles. Unlike obstructive sleep apnea, where the airway physically collapses, there is no blockage at all. The lungs simply pause because the command to breathe never arrives. CPAP can help in some cases, but many people with central sleep apnea find it uncomfortable, ineffective, or both.
The remedē System works around this gap in the brain’s signaling by sending small electrical pulses directly to the phrenic nerve, which runs from the neck down through the chest to the diaphragm. When the device detects that breathing has slowed or stopped during sleep, it delivers stimulation that causes the diaphragm to contract, mimicking a natural breath. The device activates automatically at a scheduled time each night and turns off in the morning, so there is nothing the patient needs to do. It functions like a pacemaker for breathing rather than for the heart.
Clinical Results
The pivotal trial for the remedē System randomized patients with moderate-to-severe central sleep apnea to either active treatment or a control group whose device was implanted but not turned on. At six months, 60 percent of patients in the treatment group had their breathing disruptions cut by at least half, compared to just 11 percent of the untreated controls.1PubMed Central. Long-term efficacy and safety of phrenic nerve stimulation for the treatment of central sleep apnea By 12 months, that number rose to 67 percent in the treatment group, and after the control group’s devices were activated, 55 percent of those former controls also reached the same threshold.2PubMed. Sustained 12 Month Benefit of Phrenic Nerve Stimulation for Central Sleep Apnea
A pooled analysis that combined data from multiple studies found a median reduction of about 23 breathing disruptions per hour at six months, representing roughly a 58 percent drop from baseline.3PubMed Central. Phrenic Nerve Stimulation for the Treatment of Central Sleep Apnea: A Pooled Cohort Analysis These are meaningful numbers for a condition where patients can experience 30, 40, or more pauses per hour of sleep.
How Long the Benefits Last
One of the key questions with any implantable device is whether it keeps working over time. The remedē System has data out to five years, and the results suggest durability. Breathing disruptions, blood oxygen dips, and sleep-related arousals all showed sustained improvements across the full follow-up period. Daytime sleepiness, measured by a standard questionnaire, improved by a clinically meaningful margin that held at five years.4PubMed Central. Transvenous Phrenic Nerve Stimulation for Treatment of Central Sleep Apnea: Five-Year Safety and Efficacy Outcomes
At two years in the pivotal trial, 93 percent of patients still had some degree of reduction in their breathing disruption count compared to where they started.5PubMed Central. Long-term efficacy and safety of phrenic nerve stimulation for the treatment of central sleep apnea The response rates at 12, 18, and 24 months hovered between 60 and 67 percent for the stricter outcome of halving the breathing disruption index, suggesting the device does not gradually lose effectiveness the way some therapies do.
Improvements Beyond Breathing Numbers
Reducing the number of apnea events is only part of what matters. Sleep quality itself changes. The remedē System improved sleep architecture, meaning patients spent more time in the deeper, more restorative stages of sleep and less time in the lighter stages where they are easily aroused. Arousal index, which counts how many times per hour the brain briefly wakes, dropped substantially alongside the breathing improvements.6PubMed Central. Transvenous phrenic nerve stimulation to treat idiopathic central sleep apnea
Patients in clinical studies also reported improvements in daytime fatigue, general and mental health, and social functioning on validated quality-of-life questionnaires.7PubMed Central. Transvenous phrenic nerve stimulation to treat idiopathic central sleep apnea These gains make sense: when the brain is being jolted awake dozens of times per hour all night, every part of waking life suffers. Restoring more continuous sleep ripples outward into energy, mood, and the ability to participate in normal daily activity.
Safety and Side Effects
Through 24 months, serious adverse events related to the implant procedure, the device, or the therapy itself were reported in about 10 percent of patients. Those events included things you would expect with any implanted device: lead dislodgment, infection at the implant site, interactions with other implanted devices, and occasional lead repositioning needs. All of the events resolved, either with routine medical care or with device revision or reprogramming. There were no unanticipated device-related problems and no deaths linked to the system.8PubMed Central. Long-term efficacy and safety of phrenic nerve stimulation for the treatment of central sleep apnea
The most common non-serious complaint was discomfort related to the therapy itself, which about a third of heart failure patients reported within the first year. In nearly every case, this resolved when the device was reprogrammed to adjust the stimulation settings.9European Journal of Heart Failure. Phrenic Nerve Stimulation to Treat Patients with Central Sleep Apnoea and Heart Failure An earlier feasibility study in heart failure patients found no side effects or adverse events related to the stimulation itself over the follow-up period, with only one lead dislodgment that was successfully repositioned.10PubMed. Safety and feasibility of chronic transvenous phrenic nerve stimulation for treatment of central sleep apnea in heart failure patients
The sensation of the device working overnight is something patients need to adjust to. The phrenic nerve stimulation causes the diaphragm to contract, and some people feel this, especially initially. Clinicians can fine-tune the stimulation intensity, timing, and ramp-up speed to minimize discomfort, and most patients acclimate within the first few weeks to months of use.
The Implant Procedure
The remedē System is implanted using a transvenous approach, similar in concept to how a cardiac pacemaker is placed. A surgeon accesses a vein, typically through the axillary, cephalic, or subclavian vein near the shoulder, and threads thin leads through the venous system to reach the veins that run alongside the phrenic nerve. The stimulation lead is positioned in either the left pericardiophrenic vein or the right brachiocephalic vein, depending on the patient’s anatomy. A separate sensing lead is placed to detect breathing effort, and the pulse generator is implanted in a small pocket under the skin near the chest.11PubMed Central. How to implant a phrenic nerve stimulator for treatment of central sleep apnea?
Because the leads travel through veins rather than requiring open surgery on the nerve itself, the procedure is minimally invasive. It typically takes a few hours and is performed under general anesthesia or deep sedation. However, the anatomy can be tricky. In one study tracking implantation attempts, about a quarter required additional steps like balloon dilation of narrow veins to get the lead into the right position. With those interventional techniques included, the overall implantation success rate reached 93 percent.12PubMed. Interventional techniques to increase implantation success of transvenous phrenic nerve stimulation for central sleep apnea treatment
The procedure is typically performed by cardiac electrophysiologists or interventional cardiologists because the skills involved, threading leads through veins, managing fluoroscopic imaging, and securing leads in small venous branches, overlap heavily with the skillset used in pacemaker and defibrillator implantation. This means the device can be placed at many centers that already have cardiac device programs.
Central Sleep Apnea and Heart Failure
Central sleep apnea is disproportionately common in people with heart failure. When the heart pumps less effectively, fluid shifts and altered blood chemistry can destabilize the brain’s respiratory control, creating a vicious cycle: poor sleep worsens heart failure, and worsening heart failure worsens sleep apnea. Treating the sleep apnea in this population is not just about better sleep. It is about trying to break that cycle.
In a pooled analysis of heart failure patients treated with the remedē System, the device reduced the severity of central sleep apnea, and patients reported improvements in heart-failure-specific quality of life.13PubMed Central. Phrenic nerve stimulation to treat patients with central sleep apnoea and heart failure There are also hints of cardiac benefit: in a subgroup of patients who had reduced heart function and no permanent atrial fibrillation, the heart’s pumping efficiency improved by a median of 4 percentage points after 12 months of therapy.14European Journal of Heart Failure. Phrenic Nerve Stimulation to Treat Patients with Central Sleep Apnoea and Heart Failure
That finding is encouraging but comes with caveats. The subgroup was relatively small (50 patients), and the heart volume changes were not all statistically robust. Whether phrenic nerve stimulation truly remodels the heart over time remains an open question that larger, dedicated cardiac outcome trials would need to answer. Still, the signal is biologically plausible: if you eliminate dozens of oxygen dips per night and reduce the stress responses that accompany them, you would expect some downstream cardiac benefit.
Who Responds Best
Not everyone gets the same degree of benefit from the remedē System. Researchers analyzed what characteristics predicted a strong response and found that body mass index was the most consistent predictor across analyses. Patients with lower BMI tended to respond better. Height and the proportion of breathing events classified as hypopneas (partial reductions in breathing rather than full pauses) also played a role, with taller patients and those with a higher proportion of hypopneas being more likely to reach the target of a 50 percent reduction in breathing disruptions.15PubMed Central. Long-term efficacy and safety of phrenic nerve stimulation for the treatment of central sleep apnea
This makes intuitive sense. The device works by contracting the diaphragm, and a lighter body puts less mechanical resistance against that contraction. It does not mean the remedē System is ineffective in larger patients, but it does suggest that expectations and candidate selection should take body size into account. The device is generally considered for patients whose central sleep apnea is moderate to severe and who have not responded adequately to other treatments like CPAP or adaptive servo-ventilation.
How It Differs from Obstructive Sleep Apnea Treatments
If you have heard of Inspire therapy, the hypoglossal nerve stimulator for obstructive sleep apnea, the remedē System is a fundamentally different device solving a fundamentally different problem. Obstructive sleep apnea involves the upper airway collapsing during sleep. Inspire addresses that by stimulating the hypoglossal nerve, which stiffens the tongue and opens the airway. The remedē System, by contrast, stimulates the phrenic nerve to drive the diaphragm because the issue in central sleep apnea is not a blocked airway but an absent breathing signal from the brain.
CPAP, the standard first-line therapy for obstructive sleep apnea, works for some central sleep apnea patients but is far less reliable. Positive airway pressure splints an airway open, which is exactly what you need when there is an obstruction. When the problem is that the brain is not telling the body to breathe, pressurized air alone does not always fix things. Adaptive servo-ventilation, a more sophisticated form of positive pressure therapy that adjusts breath by breath, has been used for central sleep apnea but raised safety concerns in a major trial when used in patients with heart failure and reduced heart function. That trial effectively narrowed the treatment options for a large segment of central sleep apnea patients, making the remedē System a particularly valuable alternative for those who were left without a viable therapy.
Idiopathic Central Sleep Apnea
While much of the research on the remedē System has focused on central sleep apnea in the context of heart failure, the device also works for people with idiopathic central sleep apnea, meaning cases where no clear underlying cause is found. A study specifically examining these patients reported substantial drops in breathing disruptions, central apnea events, and arousals at six, 12, and 18 months. The central apnea index fell by 22 to 23 events per hour across those time points, and quality-of-life measures showed meaningful improvements in daytime sleepiness, fatigue, and mental health.16PubMed Central. Transvenous phrenic nerve stimulation to treat idiopathic central sleep apnea
Idiopathic central sleep apnea patients are a smaller group, and they sometimes struggle even more than heart failure patients to find an effective treatment because there is no underlying condition to optimize. For them, the remedē System may be one of very few options that directly addresses the breathing control problem rather than working around it.
Insurance and Access
One of the biggest practical hurdles for the remedē System is navigating the cost and reimbursement landscape. The device, implantation procedure, and follow-up programming are expensive, and insurance coverage has been inconsistent. Some centers in the United States have built sustainable programs around the device by working through the reimbursement process with Medicare and private insurers, but it remains more complex than getting coverage for a pacemaker or defibrillator. The device has an FDA approval with a specific indication for moderate-to-severe central sleep apnea, which helps, but coverage determinations can vary by insurer and by region.
For patients considering the remedē System, the process typically starts with a sleep specialist confirming the diagnosis of central sleep apnea through a formal sleep study, followed by documentation that other treatments have been tried or considered. Prior authorization from the insurer is usually required. The implanting center often handles much of this administrative work, but patients should expect the process to take some time and potentially involve appeals.
Living With the Device
Once implanted and activated, the remedē System requires periodic follow-up visits, similar to the schedule for a cardiac pacemaker. The device can be interrogated and reprogrammed wirelessly, allowing clinicians to adjust stimulation parameters as needed. Battery life is finite, and the pulse generator will eventually need to be replaced, much like a pacemaker generator swap. This is a relatively minor outpatient procedure compared to the initial implant.
Patients do not need to wear a mask, adjust settings before bed, or remember to charge anything. The device turns on and off automatically according to its programmed schedule. For many people who have struggled with CPAP adherence, this hands-off nature is the single biggest advantage. There is no nightly decision about whether to use it, no mask to adjust, and no hose to manage. The therapy simply happens, which effectively removes adherence as a variable in treatment success.