Overnight continuous positive airway pressure is still the gold standard treatment for OSA; but for those who cannot use CPAP, this effective new technology may be an option.
The increasing incidence of obstructive sleep apnea (OSA)-a result of narrowing or closure of the upper airway when lying down-has led to an increase in conditions that are adverse pathophysiologic consequences, such as hypoxemia, hypertension, pulmonary hypertension, and excessive daytime sleepiness. Although continuous positive airway pressure (CPAP) is an effective treatment, compliance with this therapy is limited by patient factors and comfort.
A recent study published in The New England Journal of Medicine called the STAR trial, demonstrated significant improvement in the objective and subjective measurements of the severity of OSA with an implanted upper airway stimulation device. This device, which is designed to stimulate the hypoglossal nerve during sleep and thus improve the tone of the upper airway muscles, was chosen because it showed promise in early feasibility studies.
A total of 126 participants (83% men), with a mean age of 54.5 years and mean BMI of 28, who had difficulty with adherence to CPAP, underwent surgical implantation of an upper airway stimulation device. There was no control arm and all participants served as their own controls. The implantation and observational portion of the study was followed by a randomized controlled therapy-withdrawal segment. Following implantation, multiple parameters showed improvement, including the median apnea-hypopnea index (significantly decreased by 68%, from ~29 to 9 events/hr, P<.001); the Epworth Sleepiness Scale; and the oxygen desaturation index (significantly decreased by 70%, from ~25 to ~7 events/hr, P<.001). In the second phase, all of these parameters worsened in patients who had the nerve stimulator removed compared with the same measures for those who retained the nerve stimulator. The rate of adverse events related to implantation or explantation was low at <2%.
Although this study should be carefully interpreted with its limitations (unblinded, mean BMI 28, industry-funded, small sample size), it does raise the possibility of an exciting new alternative for the many patients who cannot adhere to CPAP therapy. It also highlights the evolving trend in medicine toward procedure-based therapies for medical conditions that are refractory or challenging to treat. Finally, it highlights that even with the availability of such interventions, there are still residual consequence of OSA, such as weight loss and diet control, that warrant “traditional” approaches.
Strollo PJ, Soose RJ, Maurer JT, et al. The STAR trial group. Upper-airway stimulation for obstructive sleep apnea. N Engl J Med 2014;370:139-149.