Implant reduces sleep apnea in post-marketing studies

A pacemaker-type implant that stimulates the nerves in the upper airway of patients with obstructive sleep apnea (OSA) showed significant reductions in apnea symptoms, increased oxygen desaturation, and better quality of life, according to presentations given at SLEEP 2016, the 30th annual meeting of the Associated Professional Sleep Societies, held June 11-15, 2016 in Denver, CO.

The device is considered a second-line surgical alternative for sleep apnea patients who can’t tolerate continuous positive airway pressure (CPAP). It consists of a pacemaker implanted in the chest and two wires to stimulate the hypoglossal nerve of the tongue. Patients use a remote control to turn on the device before going to sleep and turn it off upon waking. After the patient falls asleep, the device detects the patient’s breathing pattern and the pacemaker’s pulse generator stimulates the hypoglossal nerve to enlarge the upper airway. 

“There is no perfect treatment option for obstructive sleep apnea, but our preliminary data suggest that hypoglossal nerve stimulation can effectively treat patients with sleep apnea who are unable to tolerate CPAP,” said presenter Richard Schwab, MD, co-medical director of the Penn Sleep Center at the Perelman School of Medicine at the University of Pennsylvania, in Philadelphia, PA.

Although the device was approved in April 2014, these are some of the first reports to show that the stimulator reduces OSA symptoms not only in the sleep lab, but in patients’ homes.

“Considering that sleep apnea can lead to high blood pressure, heart attack, stroke, and other serious health problems, it is critically important that we study devices that may serve as another option instead of CPAP to treat patients with sleep apnea,” Dr. Schwab noted.

In this presentation, Dr. Schwab and Penn Sleep Center researchers reported on 20 patients who underwent surgical implantation between January 2015 and March 2016. These patients were overweight, middle aged, and had severe OSA. After implantation, the total apnea-hypopnea index (AHI) for all patients significantly decreased an average of 35 events per hour—a reduction of 84%. Additionally, the lowest oxygen desaturation level significantly increased by an average of 11%, from 79% to 90%, the Penn researchers reported.

In a separate presentation, researchers from Thomas Jefferson University and University of Pittsburgh Medical Center described similar reductions in AHI measures and improved oxygen desaturation levels in 40 patients with the implant. They also reported an average 60% improvement in patients’ daytime sleepiness scores.

A study by University of South Florida researchers looked at the effect of hypoglossal nerve stimulation on reducing blood pressure in 12 patients with OSA. But in contrast to the device’s clinical trial findings, this small study found no statistically significant decrease in systolic or diastolic blood pressure readings.

“This case series invites further long-term monitoring of health measures (ie, BMI, development of diabetes, cardiac/all-cause mortality) in patients with continued use of hypoglossal nerve stimulation for treatment of OSA,” these researchers concluded.