Phrenic Nerve Stimulation for Treatment of Central Sleep Apnea

This is a multi-center prospective cohort study to monitor the effect of bilateral phrenic
nerve stimulation for treatment of central sleep apnea (CSA) in patients with heart failure.
There will be 2 groups of study patients, both with CSA and heart failure. One group will
receive the phrenic nerve pacer, and one will not. Both groups will have the same medical
oversight, management, and assessment of heart health whether they receive the pacer or not.

Subjects will have a physical exam, review of medications, New York Heart Association (NYHA)
functional classification assessment for heart failure, Minnesota Living With Heart Failure
(MLWHF) Questionnaire for quality of live assessment and blood test for Pro-BNP. In-lab sleep
study will be required if subject haven't had one within 3 months, and Echocardiogram, if
subjects haven't had one within 30 days. If subjects are willing to have stimulator placement
procedure, they'll have an ENT consult. Subjects in the procedure arm will have Phrenic Nerve
Stimulator placement procedure, and 3 weeks after procedure follow up visit with ENT doctor
to activate the device and have sleep study to confirm proper settings.

Inclusion Criteria:

- 1. Male or female, age 18 to 80 years inclusive.

2. New York Heart Association (NYHA) class III or IV, or NYHA class II with an episode
of heart failure requiring hospitalization in the past 24 months.

3. Stable on guide line directed medical therapy (GDMT) for 30 days prior to
enrollment.

4. Moderate or severe sleep apnea, that is an Apnea Hypopnea Index (AHI) of >15/hour
with >50% being central apneas.

5. Willing and able to provide written informed consent in compliance with the
regulatory requirements. If a subject is unable to provide written informed consent,
written informed consent may be obtained from the subject's legal representative.

Exclusion Criteria:

1. Phrenic nerve palsy.

2. Baseline hypoxia (oxygen saturation <90% on room air).

3. On supplemental oxygen.

4. Severe COPD.

5. Unstable angina, MI or cardiac procedure within 3 months of phrenic nerve stimulator
placement.

6. Unwilling or unable to comply with the requirements of this protocol, including the
presence of any condition (physical, mental, or social) that is likely to affect the
subject's ability to comply with the protocol.

7. Any other reasons that, in the opinion of the Investigator, the candidate is
determined to be unsuitable for entry into the study.