Sleep Apnea Intervention for Cardiovascular Disease Reduction

In this pilot randomized controlled trial, we will assess the effectiveness of CPAP therapy to reduce the burden of cardiovascular disease (CVD) and CVD risk factors in patients with moderate to severe obstructive sleep apnea (OSA) presenting to a sleep disorders clinic. A total of 700 patients with a new diagnosis of moderate to severe OSA will be recruited from BWH-affiliated sleep disorder clinics, BWH, Massachusetts General Hospital (MGH), and Faulkner Hospital Cardiology Clinics (and similar specialized clinics seeing patients with cardiovascular risk factors, such as endocrinology and hypertensive clinics), Beth Israel Deaconess Medical Center and Joslin Diabetes Center. After completing a 2 week run-in period, randomized participants (approximately 150 participants will be randomized) will undergo baseline and 6 month assessments of key study exposure and outcome variables.

Participants will be randomized after completion of Baseline visit. The treatment arms are as follows:

The active arms are:

• Active-PAP treatment delivered using standard respiratory therapist (RT) adherence education and support. (Active-Beh)
• Active-PAP treatment administered using adherence education and support delivered by a RT and enhanced by a behavioral promotion intervention. (Active+Beh)

The control arms are:

• Conservative Medical Therapy (CMT)
• Sham-PAP (Sham)

Participants randomized before December 31, 2012 (n=108) also will undergo 12 month follow-up assessments. Participants will be offered a 12 month supervised conservative medical therapy (CMT) program for OSA over the duration of the study intervention. Subjects would be contacted at bimonthly intervals by alternating phone and office visits to assess safety, identify adverse events, identify health care utilization, and reinforce protocol adherence. At 6 and 12 months, study outcomes will be reassessed by collecting data from sources.

Patients randomized after December 31, 2012 (n=61) will undergo only 6 months of follow-up assessment. Participants will be offered a 6 month supervised conservative medical therapy (CMT) program for OSA over the duration of the study intervention. Subjects would be contacted at bimonthly intervals by alternating phone and office visits to assess safety, identify adverse events, identify health care utilization, and reinforce protocol adherence. At 6 months, study outcomes will be reassessed by collecting data from sources.

Inclusion criteria

• Obstructive apnea hypopnea index (AHI) ≥ 15
• Age 45-75 years, or 55 to 75 yrs if without established Cardiovascular Disease (CVD)
• Ability to provide informed consent, with the patient and physician acknowledging accepting uncertainty on the role of PAP in CVD prevention.
• Established CVD,or having diabetes mellitus, defined by one or more of the following:

• Prior myocardial infarction
• Coronary artery revascularization procedure (≥4 months before study entry)
• Angiographically documented stenosis (>70%) of a major coronary artery
• Prior ischemic stroke without major functional impairment
• Diabetes mellitus treated with medication or ≥ 2 fasting glucose levels ≥ 126 mg/dl

OR

Three or more of the following established CVD risk factors:

• Hypertension treated with medications or systolic BP > 140 or diastolic BP > 90 on ≥ 2 occasions
• Male sex
• BMI ≥ 30
• Total cholesterol > 240 mg/dl or LDL cholesterol > 160 mg/dl or HDL < 45 mg/dl
• > 10 pack years of smoking

Exclusion criteria

• Diagnosed heart failure with known cardiac ejection fraction of < 35% or New York Heart Association (NYHA) class 3 or 4 status
• Less than 4 months since myocardial infarction (MI), stroke or revascularization procedure
• Poorly controlled hypertension (>170/>100)
• Prior stroke with functional impairment interfering with ability to complete the protocol
• Severe uncontrolled medical problems or medications that may influence measurements or impair ability to participate in the study exams (e.g. oral steroids; chronic opioid use; self- reported chronic kidney disease or, if measured, creatinine > 2.5 mg/dl or glomerular filtration rate (GFR) < 30; anemia with Hgb < 10, etc.)
• Resting oxygen saturation < 90% or nocturnal oxygen saturation <85% for > 10% of the sleep period;
• Use of prescribed PAP for sleep apnea within the prior 2 years
• Report of inability to spend >6 hrs in bed
• Any use of prescribed PAP for sleep apnea
• Severe sleepiness defined by an Epworth Sleepiness Score of >14 or report of falling asleep driving in the prior 2 years
• Working as a professional driver
• Low risk related to having sleep apnea defined by a Berlin Score < 2
• Central sleep apnea, with >50% of respiratory events classified as central apneas
• Refusal to consider PAP use after an initial split-night PAP study (pre-randomization)
• Concurrent involvement in another research study that will result in a conflict as determined by study doctors