Sleep Apnea Cardiovascular Endpoints (SAVE) Study

Although obstructive sleep apnea (OSA) is a very common condition that is associated with an increased risk of cardiovascular disease (CVD), there is much uncertainty over the effectiveness of treatment with nasal continuous positive airway pressure (CPAP) for the prevention of CVD. Only a large-scale clinical trial could resolve this uncertainty and if positive, radically change clinical practice so that screening for OSA is part of the routine CVD risk assessment.

SAVE is a multi-centre, open label, parallel, prospective, randomised, controlled trial of CPAP treatment plus standard care versus standard care alone, in 2500 high CVD risk subjects with moderate-severe OSA. The trial will determine the effects of CPAP treatment over a two to seven year follow-up period on new cardiovascular events, including myocardial infarction, stroke and cardiovascular death.

Issue

There is now wide-ranging evidence that OSA may be a risk factor in the development of cardiovascular disease. Large population studies have demonstrated associations with:

  • Increased blood pressure
  • Stroke
  • Acute coronary syndromes
  • Heart failure
  • Sudden death

Cardiovascular disease is the leading cause of global disease burden and is predicted to increase, particularly in low-middle income nations, due to ageing and lifestyle changes. Given the above associations, OSA is a potential important modifiable risk factor.

CPAP is well-established as an effective treatment to improve the daytime sleepiness associated with OSA, as well as improving other markers of the disease (nocturnal oxygen saturation, sleep fragmentation, quality of life measures). There is limited evidence suggesting CPAP can also improve cardiovascular risk factors; however previous studies have not definitively demonstrated that CPAP treatment reduces cardiovascular mortality and morbidity.

Since OSA is highly prevalent and amenable to cost-effective treatments, a major advancement in health care could be made if it can be established reliably that OSA is a significant cause of cardiovascular events, and premature death and disability. It is anticipated that screening for OSA would then become part of routine clinical care in cardiovascular medicine, and integrated within public health campaigns aimed at reducing cardiovascular morbidity and mortality.

Methods

SAVE is a multi-centre, open label, parallel, prospective, randomised, controlled trial of CPAP treatment plus standard care versus standard care alone, in high CVD risk subjects with moderate-severe OSA.

Global study

The study is conducted in China, Australia, New Zealand, India, USA, Spain and Brazil.

China

The Save Trial China-Australia collaborative, multi-centre program of research to establish the benefits of treatment of obstructive sleep apnea (OSA) on cardiovascular outcomes. There is currently relatively little community awareness of OSA in China compared to developed countries. Additionally access to treatment is severely restricted by cost - CPAP is currently beyond the means of nearly all sufferers of OSA. Thus the vast majority of cases in China currently go undetected and untreated.

Executive committee

  • Associate Professor Nick Antic
  • Professor Ron Grunstein
  • Professor Jan Hedner
  • Professor Shaoguang Huang
  • Professor Geraldo Lorenzi-Filho
  • Professor Susan Redline
  • Professor Jiguang Wang
  • Professor Nanshan Zhong

Status

Recruitment finished in December 2013, with 2717 patients recruited from 89 centres worldwide. Follow up visits will be continuing until the end of 2015.

If the results of the SAVE study prove positive it will be a major advance for the sleep apnea field and will place OSA in the mainstream of cardiovascular medicine.

Projects leads

Further reading