Sleep apnoea (SA) is associated with a range of conditions, such as hypertension, coronary artery disease, arrhythmias and diabetes, to name a few. And now researchers have explored the link between SA and heart failure (HF), with interesting results.
A recent study, published in Journal of the American Heart Association, has shown that continuous positive airway pressure (CPAP) therapy can reduce the risk of HF in patients with SA. 
In this study, Danish nationwide databases were used to follow 4.9 million people from 2000 to 2012. Of these, 45,485 individuals developed SA, 45.2 percent of whom received CPAP therapy. The end points were HF, defined as first-time primary or secondary diagnosis at hospitalisation or during outpatient visits.
Notably, those receiving CPAP therapy were older (median age of 55.7 years) than patients with SA without CPAP (52.4 years), and those in the background population (43.1 years). Furthermore, patients receiving CPAP therapy had a higher rate of comorbidities and concomitant pharmacotherapy than the other groups.
The incidences of HF in patients with untreated SA were significantly higher than those in patients with SA receiving CPAP therapy. Furthermore, patients aged over 60 years who received CPAP had a lower risk of HF than those with SA who were not receiving CPAP.
These findings are significant. Patients with SA who are not treated with CPAP are at an increased risk of developing HF; and patients over 60 years who are receiving CPAP have a lower risk of HF compared to the other groups.
Lead author Dr. Anders Holt, Department of Cardiology at Copenhagen University in Denmark, tells Medical Xpress that: “It is indisputable in a study with this many patients that sleep apnoea patients as a group do in fact develop more heart failure than the general public, although the observational study design makes it hard to determine a cause-and-effect relationship,”
“This should encourage doctors caring for sleep apnoea patients to pay extra attention to monitoring and treating other cardiovascular risk factors, as well as the sleep apnoea.” 
Therefore, although CPAP therapy is used primarily to treat the symptoms of SA, it has potential as an effective treatment for reducing the risk of HF in this patient population. As the study authors state, more research is needed. However, as Dr Holt adds, this study sends a “clear, reassuring signal” about the benefits of CPAP therapy for patients with heart failure. 
It is interesting that sleep apnea patients above 65 years of age might have an increased risk of developing heart failure and that treating these patients with CPAP therapy could possibly eliminate that increased risk. Even though the study design is observational and we should be careful concluding on causality, these findings generate a strong hypothesis which should be investigated further.
The US preventive service task force issued a recommendation in 2017 not to screen for OSA due to insufficient evidence on benefits and harms of a screening program and, especially, due to the lack of evidence concerning the potential beneficial effect of CPAP therapy on hard outcomes. 1 We believe that this study adds important data to this discussion and should encourage more studies focusing on the possible cardiovascular risks of sleep apnea, as well as establishing CPAP therapy’s effect on cardiovascular outcomes.
The SERVE-HF trial rose concern regarding the use of pressure therapies for sleep apnea patients with heart failure since it showed an increased mortality among the sleep apnea patients treated with adaptive servo-ventilation (ASV). Although the studies cannot be compared due to unequal patients and differing ventilation therapies, it is reassuring to find that CPAP therapy appears completely safe in a large cohort of sleep apnea patients. 2
Sleep apnea is a very underdiagnosed condition, and the increasing evidence of associated risks and the potential beneficial effects of CPAP therapy should encourage both patients and clinicians to focus on diagnosing and treating sleep apnea.
- Bibbins-Domingo K, Grossman DC, Curry SJ, Davidson KW, Epling JW, García FAR, Herzstein J, Kemper AR, Krist AH, Kurth AE, Landefeld CS, Mangione CM, Phillips WR, Phipps MG, Pignone MP, Silverstein M, Tseng C-W. Screening for Obstructive Sleep Apnea in Adults. JAMA. 2017;317:407.
- Cowie M, Woehrle H, Wegscheider K, Angermann C, D’Ortho M, Erdmann E, Levy P, Simonds A, Somers V, Zannad F, Teschler H. Adaptive Servo-Ventilation for Central Sleep Apnea in Systolic Heart Failure. N Engl J Med. 2015;373:1095–1105.