Sleep apnea device shows clinical benefit for HF patients in pilot study

ORLANDO, Fla. — A novel, implantable sleep apnea device showed clinical benefit for the treatment of central sleep apnea, according to results of a pilot study presented at the Annual Scientific Meeting of the Heart Failure Society of America.

The transvenous phrenic nerve stimulator (remedē System, Respicardia) is designed to restore normal sleep and breathing to improve respiratory and CV health in patients with central sleep apnea. The device is implanted below the collarbone by electrophysiologists using a procedure similar to the implantation of intracardiac devices, according to a press release.

About 35% of patients with HF have central sleep apnea, and about 2.1 million people in the United States are affected, said William T. Abraham, MD, director of cardiovascular medicine at The Ohio State University Wexner Medical Center. The device “gives impulses on a regular basis [to a phrenic nerve] to regularize breathing, avoiding the highs … of hyperventilation and the lows … of apnea.”

William T. Abraham

The remedē System Pilot Study is the first prospective, international, multicenter, nonrandomized trial to investigate use of this device in patients with central sleep apnea. Researchers enrolled 57 patients aged 18 years or older; 49 (89% men; mean left ventricular ejection fraction 30.5%) were implanted successfully, 47 were available for follow-up at 3 months and 44 were available for follow-up at 6 months. All patients had a baseline apnea-hypopnea index of ≥20. Patients with HF were stable, and medications were optimized and stable for at least 30 days.

Abraham presented the results at a late-breaking clinical trials session. Mean apnea-hypopnea index improved from 49 at baseline to 23 at 3 and 6 months (P≤.0001). Central apnea index improved from 28 at baseline to 5 at 3 and 6 months (P≤.0001). Patients experienced further improvements in mean oxygenation of more than 50% and reported decreased arousal index (36 events/hour at baseline vs. 23 events/hour at 3 months and 25 events/hour at 6 months; P≤.0001). Thirty-five patients surveyed at 6 months said their quality of life had improved; only one said it worsened, according to Abraham. Mean systolic BP changed from 125 mm Hg at baseline to 122 mm Hg at 6 months (P=.4198), and mean diastolic BP remained unchanged from 74 mm Hg at baseline to 74 mm Hg at 6 months (P=.9435).

“[The findings provide] definitive proof of concept that we can regularize the respiratory rhythm, that is we can regularize respirations and avoid central sleep apneas in HF and other CVD patients,” Abraham told Cardiology Today.

“The remedē System therapy shows promise for the treatment of central sleep apnea and warrants further study,” he said during the presentation.

In an invited commentary at the meeting, Christopher M. O’Connor, MD, chief of the division of cardiology at Duke University Medical Center, said central sleep apnea is a major problem for HF patients and the respiratory rhythm management system could be of great benefit.

“There are currently over 40 studies on sleep disorders in patients with HF,” O’Connor said. “This is an active, exciting field, and [respiratory rhythm management] is one of the most exciting areas of study in it.”

The device will next be tested in a randomized controlled trial of approximately 150 patients. Enrollment began a few weeks ago, Abraham said. – by Erik Swain

For more information:

Abraham WT. Late Breaking Clinical Trials. Presented at: the Annual Scientific Meeting of the Heart Failure Society of America; Sept. 22-25, 2013; Orlando, Fla.

Disclosure: Abraham is a consultant for Respicardia. O’Connor reports financial ties with Actelion Pharmaceuticals, Amgen, Biscardia, Faculty Connection, Neurotronik/Interventional Autonomics Corp., Novella Clinical, ResMed and Synecor.