Oxygen Versus PAP for Sleep Apnea in Heart Failure

Phase 4

Completed

Interventions: Device: Continuous positive airway pressure
Device: Nocturnal supplemental oxygen
Behavioral: Healthy Lifestyle and Sleep Education

Brief Summary: The purpose of this study is to compare three treatment modalities for central, or mixed obstructive and central, sleep apnea in patients with chronic heart failure and reduced ejection fraction. The modalities to be tested are nocturnal supplemental oxygen (NSO) and continuous positive airway pressure (CPAP). The main outcome measures will be left ventricular ejection fraction on echocardiogram and peak oxygen consumption on cardiopulmonary exercise testing.

Detailed Description: Chronic heart failure (HF) is a highly prevalent disease, with a lifetime risk of approximately 20%. Sleep apnea is a common co-morbid condition, occurring in approximately half of patients with chronic HF, and often has predominantly central or mixed obstructive and central characteristics. Although it is associated with increased mortality in patients with HF, sleep apnea is usually asymptomatic and patients are therefore often unwilling to accept standard therapy with positive airway pressure. At the outset of this study, there were three treatment modalities currently recommended by the American Academy of Sleep Medicine for the treatment of predominantly central sleep apnea in HF patients: nocturnal supplemental oxygen (NSO), continuous positive airway pressure (CPAP) and adaptive servo-ventilation (ASV). Recently, ASV was found to increase mortality in patients with heart failure with reduced ejection fraction and central sleep apnea. There are only limited data on the comparative efficacy and tolerability of these three modalities. The present study is designed to compare these modalities with respect to effects on ventricular function, exercise capacity, and other measures of cardiovascular risk.

Recruitment & Eligibility

Inclusion Criteria

Veteran receiving care within the Veterans Health Administration healthcare system
Age 18 years
Physician diagnosis of chronic heart failure, American Heart Association Stage C-D
LVEF <45%
No change in active cardiac medications for 4 weeks prior to randomization
Ability to provide informed consent
Moderate to severe central or mixed central and obstructive sleep apnea, defined as an apnea-hypopnea index (AHI) 15 events per hour, with a central AHI >5 events/hour

Exclusion Criteria

Hospitalization for acute decompensated HF within previous 30 days
Hospitalization for myocardial infarction or cardiac surgery within previous 90 days
Presence of a left ventricular assist device
History of heart transplantation
Poorly controlled hypertension (>170/>110)
Poorly controlled diabetes (HbA1c > 9.0)
Severe renal failure with estimated glomerular filtration rate <30 ml/min
Prior stroke with functional impairment or other severe, uncontrolled medical problems that may impair ability to participate in the study exams, based on medical history and review of medical records
Severe chronic insomnia, with reported usual sleep duration <4 hours
Severe daytime sleepiness, defined as Epworth Sleepiness Scale score 18 or higher or a report of falling asleep driving during the previous year, and deemed a safety risk by study physician
Awake resting oxyhemoglobin saturation <89%
Pregnancy
Smoking by subject or other person in the subject's bedroom, or other open flame in bedroom
Current use of a positive airway pressure device (including continuous or bi-level positive airway pressure or adaptive servo-ventilation) or supplemental oxygen therapy

Arm && Interventions

Group	Intervention	Description
CPAP	Continuous positive airway pressure	Nocturnal continuous positive airway pressure
NSO	Healthy Lifestyle and Sleep Education	Nocturnal supplemental oxygen
HLSE	Healthy Lifestyle and Sleep Education	Healthy lifestyle and sleep education control
CPAP	Healthy Lifestyle and Sleep Education	Nocturnal continuous positive airway pressure
NSO	Nocturnal supplemental oxygen	Nocturnal supplemental oxygen

Primary Outcome Measures

Name	Time	Method
Left Ventricular Ejection Fraction	3 months	Standard transthoracic 2-dimensional and Doppler echocardiography will be performed. M-mode measurements of LV dimensions will be performed and analyzed according to the American Society of Echocardiography recommendations and LVEF measured using the modified Simpson's method. Measurement is change from baseline in LVEF.

Secondary Outcome Measures

Name	Time	Method
Peak Oxygen Consumption (VO2 Peak)	3 months	Treadmill exercise testing will be performed using a motor-driven treadmill and a modified Naughton protocol, with a lightweight disposable pneumotach device positioned in the participant's mouth interfaced with a metabolic cart. Change in VO2 peak between baseline and final visit will be the co-primary outcome of the study. Secondary outcome measures from cardiopulmonary exercise testing include VO2 at anaerobic threshold and VE/VCO2 slope.
24-hour Ambulatory Blood Pressure	3 months	24-hour blood pressure will be measured using a blood pressure cuff that is connected by rubber tubing to a small pressure monitoring device, programmed to measure BP at 20 minute intervals during the day and 30 minute intervals at night (11 PM to 7 AM) for a period of 24 hours. The investigators will assess 24-hour mean arterial pressure as the primary blood pressure outcome, with additional assessment of nocturnal versus diurnal blood pressure effects.

Locations (2): VA Boston Healthcare System Jamaica Plain Campus, Jamaica Plain, MA
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Boston, Massachusetts, United States
VA Connecticut Healthcare System West Haven Campus, West Haven, CT
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West Haven, Connecticut, United States