A Study of Continuous Positive Airway Pressure Treatment for Obstructive Sleep Apnea to Prevent Cardiovascular Disease


  • Study type

  • Study phase

  • Study IDs

  • Describes the nature of a clinical study. Types include:

    • Observational study — observes people and measures outcomes without affecting results.
    • Interventional study (clinical trial) — studies new tests, treatments, drugs, surgical procedures or devices.
    • Medical records research — uses historical information collected from medical records of large groups of people to study how diseases progress and which treatments and surgeries work best.
  • During the early phases (phases 1 and 2), researchers assess safety, side effects, optimal dosages and risks/benefits. In the later phase (phase 3), researchers study whether the treatment works better than the current standard therapy. They also compare the safety of the new treatment with that of current treatments. Phase 3 trials include large numbers of people to make sure that the result is valid. There are also less common very early (phase 0) and later (phase 4) phases. Phase 0 trials are small trials that help researchers decide if a new agent should be tested in a phase 1 trial. Phase 4 trials look at long-term safety and effectiveness, after a new treatment has been approved and is on the market.

  • Site IRB
    • Rochester, Minnesota: 11-002685
    NCT ID: NCT00738179
    Sponsor Protocol Number: SAVE

About this study

Obstructive Sleep Apnea (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 during sleep and 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 continuous positive airway pressure (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.

Participation eligibility

Participant eligibility includes age, gender, type and stage of disease, and previous treatments or health concerns. Guidelines differ from study to study, and identify who can or cannot participate. If you need assistance understanding the eligibility criteria, please contact the study team.

See eligibility criteria

Inclusion Criteria

  • Male or female
  • Any race
  • Age between 45 and 75 years
  • Evidence of established coronary artery disease
    • Multi-vessel coronary artery bypass surgery (CABG) >1 year prior to ApneaLink™ assessment
    • Multi-vessel percutaneous angioplasty (PTCA) and/or stent equal to or greater than 90 days prior to ApneaLink™ assessment
    • Stable angina or unstable angina clinical event equal to or greater than 30 days and confirmatory test equal to or greater than 7 days prior to ApneaLink™ assessment
    • Defined as either
      • ≥70% diameter stenosis of at least one major epicardial artery segment
      • ≥50% diameter stenosis of the left main coronary artery
      • >50% stenosis in at least two major epicardial arteries
      • Positive stress test with ST depression equal to or greater than 2 mm or a positive nuclear perfusion scintigram
    • Previous MI equal to or greater than 90 days prior to ApneaLink™ assessment
  • Evidence of cerebrovascular disease
    • Previous stroke includes definite or presumed cerebral ischaemia/infarction and intracerebral but not subarachnoid haemorrhage equal to or greater than 90 days prior to ApneaLink™ assessment 
    • Minor disabling stroke with minimal residual neurological disability and modified Rankin Score of '0 = no symptoms' or '1 = No significant disability despite symptoms, able to carry out all usual duties and activities' within 7 days of stroke onset at ≥7 days prior to ApneaLink™ assessment
    • Previous transient ischaemic event (TIA) of the brain or retina (symptoms <24 hours) but not of presumed vertebrobasilar system ischemia, and diagnosis must be confirmed by a suitably qualified clinician ≥7 days but <1year prior to ApneaLink™ assessment
  • Moderate-severe OSA equivalent to apnea plus hypopneas index [AHI] >30 per hour of sleep as determined by a ≥ 4% oxygen dip rate > 12/ h on overnight testing using the ApneaLink™ device, and confirmed by the SAVE core lab in Adelaide upon receipt of the ApneaLink™ data
  • Able and willing to give appropriate informed consent

Exclusion Criteria

  • Any condition that in the opinion of the responsible physician or investigator makes the potential participant unsuitable for the study
    • Co-morbid disease with severe disability or likelihood of death
    • Significant memory, perceptual, or behavioural disorder
    • Neurological deficit (e.g. limb paresis) preventing self administration of the CPAP mask
    • Contraindication to CPAP use e.g. pneumothorax
    • Residence sufficiently remote from the clinic to preclude follow-up clinic visits
  • Any planned coronary or carotid revascularisation procedure in the next 6 months
  • Severe respiratory disease defined as
    • Severe chronic obstructive pulmonary disease (FEV1/FVC < 70% and FEV1 < 50% predicted)
    • Resting, awake SaO2 < 90% by ApneaLink™ device
  • New York Heart Association (NYHA) categories III-IV of heart failure
  • Other household member enrolled in SAVE trial or using CPAP
  • Prior use of CPAP treatment for OSA
  • Increased risk of a sleep-related accident and/or excessive daytime sleepiness, defined by any one of the following:
    • Driver occupation (eg truck, taxi)
    • 'Fall-asleep' accident or 'near miss' accident in previous 12 months
    • High (> 15) score on the Epworth Sleepiness Scale
  • Severe nocturnal desaturation documented on the ApneaLink™ device as > 10% overnight recording time with arterial oxygen saturation of < 80%
  • Cheyne-Stokes Respiration (CSResp)
    • CSResp identified on ApneaLink™ nasal pressure recording by typical crescendo-decrescendo pattern of respiration with associated apneas and/or hypopneas in the absence of inspiratory flow limitation
    • Exclusion if > 50% of nasal pressure - defined apneas and hypopneas judged to be due to CSResp

Participating Mayo Clinic locations

Study statuses change often. Please contact us for help.

Mayo Clinic Location Status

Rochester, Minn.

Mayo Clinic principal investigator

Sean Caples, D.O., M.S.

Closed for enrollment


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