None listed
Conditions
Brief summary
OSA is a condition in which a person stops breathing for several seconds at a time due to relaxation of the throat muscles. This can occur many times over during sleep. It is known to cause sleepiness and poor concentration during the day. Research indicates that OSA may be a modifiable risk factor for cardiovascular disease due to its association with hypertension, stroke, heart attack and sudden death. The standard therapy for symptomatic OSA is CPAP. CPAP has been shown to effectively reduce snoring, obstructive episodes and daytime sleepiness and to modestly reduce blood pressure and other risk factors for cardiovascular disease. The overall aim of SAVE is to determine if CPAP can reduce the risk of heart attack, stroke or heart failure for people with OSA.
Interventions
Patients allocated to the CPAP group will be commenced on fixed level CPAP (90th centile of pressures determined during a 1 week treatment period using auto CPAP). Adherence will be monitored using the in-built monitor in each CPAP device. Treatment with CPAP involves a mask placed over the nose, or both the nose and mouth during sleep. The mask is attached via a hose to a CPAP machine, which gently pushes air into the lungs opening the obstructed airways. Treatment will continue for 2-7 years
Patients allocated to the CPAP group will be commenced on fixed level CPAP (90th centile of pressures determined during a 1 week treatment period using auto CPAP). Adherence will be monitored using the in-built monitor in each CPAP device. Treatment with CPAP involves a mask placed over the nose, or both the nose and mouth during sleep. The mask is attached via a hose to a CPAP machine, which gently pushes air into the lungs opening the obstructed airways. Treatment will continue for 2-7 years post randomisation depending on the patient’s date of enrolment. In addition, patients will receive standard care of their CV co-morbidities as directed by their regular doctor(s). Patients who continue to use CPAP (even on an intermittent basis) will have the treatment continued indefinitely.
Sponsors
Respironics Sleep and Respiratory Research Foundation
Study design
Allocation
Randomised controlled trial
Intervention model
Parallel
Primary purpose
Prevention
Masking
Open (masking not used)
Eligibility
Sex/Gender
All
Age
45 Years to 75 Years
Healthy volunteers
No
Inclusion criteria
1. Males and females, any race, and aged between 45 and 75 years 2. Evidence of established coronary or cerebrovascular disease as evident by; (a) Coronary artery disease. i. Previous MI (greater than or equal to 90 days prior to ApneaLinkTM assessment); or ii. Stable angina or unstable angina (Clinical event greater than or equal to 30 days and confirmatory test equal to or greater than 7 days prior to ApneaLinkTM assessment) defined as either greater than or equal to 70% diameter stenosis of at least one major epicardial artery segment, or greater than or equal to 50% diameter stenosis of the left main coronary artery, or greater than 50% stenosis in at least two major epicardial arteries, or positive stress test (ST depression greater than or equal to 2 mm or a positive nuclear perfusion scintigram); or iii. Multi-vessel percutaneous angioplasty (PTCA) and/or stent greater than or equal to 90 days prior to ApneaLinkTM assessment; or iv. Multi-vessel coronary artery bypass surgery (CABG) greater than 1 year prior to ApneaLinkTM assessment (b) Cerebrovascular disease i. Previous stroke (includes definite or presumed cerebral ischaemia/infarction and intracerebral but not subarachnoid haemorrhage) greater than or equal to 90 days prior to ApneaLinkTM assessment; or or minor disabling stroke with minimal residual neurological disability (modified Rankin Score of ‘0 equal to no symptoms’ or ‘1 equal to No significant disability despite symptoms, able to carry out all usual duties and activities’ within 7 days of stroke onset) greater than or equal to 7 days prior to ApneaLinkTM assessment; or ii. Previous transient ischaemic event (TIA) of the brain or retina (symptoms less than 24 hours) but not of presumed vertebrobasilar system ischemia. The TIA diagnosis must be confirmed by a suitably qualified clinician (greater than or equal to 7 days but less than 1 year prior to ApneaLinkTM assessment) 3. Patients have moderate-severe OSA (equivalent to apnea plus hypopneas index [AHI] greater than 30 per hour of sleep) as determined by a greater than 4% oxygen dip rate greater than 12/ h on overnight testing using the ApneaLinkTM device and confirmed by the SAVE corelab in Adelaide upon receipt of the ApneaLink data; and 4. Patients are able and willing to give appropriate informed consent
Exclusion criteria
Patients will be excluded from entry if ANY of the criteria listed below are met: 1. Any condition that in the opinion of the responsible physician or investigator makes the potential participant unsuitable for the study. For example, i. co-morbid disease with severe disability or likelihood of death ii. significant memory, perceptual, or behavioural disorder iii. neurological deficit (eg. limb paresis) preventing self administration of the CPAP mask iv. contraindication to CPAP use e.g. pneumothoraxv residence sufficiently remote from the clinic to preclude follow-up clinic visits 2. Any planned coronary or carotid revascularisation procedure in the next 6 months 3. Severe respiratory disease defined as i. severe chronic obstructive pulmonary disease (FEV1/FVC greater than 70% and FEV1 less than 50% predicted), or ii. resting, awake SaO2 less than 90% by ApneaLinkTM device 4. New York Heart Association (NYHA) categories III-IV of heart failure 5. Other household member enrolled in SAVE trial or using CPAP 6. Prior use of CPAP treatment for OSA 7. Increased risk of a sleep-related accident and/or excessive daytime sleepiness, defined by any one of the following: i. driver occupation (eg truck, taxi) ii. ‘fall-asleep’ accident or ‘near miss’ accident in previous 12 months iii. high (greater than 15) score on the Epworth Sleepiness Scale 8. Severe nocturnal desaturation documented on the ApneaLinkTM device as i. greater than 10% overnight recording time with arterial oxygen saturation of less than 80% 9. Cheyne-Stokes Respiration (CSResp) i. CSResp identified on ApneaLinkTM nasal pressure recording by typical crescendo-decrescendo pattern of respiration with associated apneas and/or hypopneas in the absence of inspiratory flow limitation. ii. patients excluded if greater than 50% of nasal pressure – defined apneas and hypopneas judged to be due to CSResp.
Outcome results
None listed