One of the most serious dangers of sleep apnea is heart-related complications, such as heart failure and stroke. The hope is that treating sleep apnea could reduce these risks. Unfortunately, the evidence has shown–again–that this doesn’t seem to be the case. A new study shows that people prescribed CPAP for sleep apnea aren’t seeing lower heart risks.
Randomized Clinical Trial Data Shows Limited Benefit
The new study is noteworthy for its placement. The Journal of the American Medical Association (JAMA) is one of the most prestigious medical journals in the world, and its articles are subject to rigorous scrutiny and review. The study is also noteworthy because the 10 studies utilized in the analysis are all randomized clinical trials (RCTs). RCTs are considered the best way to test the effectiveness of a treatment. People with a condition are randomly assigned to different treatments, placebos, or no treatment to see how effective the treatment can be.
The RCTs were fairly sizeable, too, so this analysis covers nearly 7300 patients, which should give it statistical power to show benefits. And it did show some benefits of CPAP. CPAP reliably reduced symptoms of sleep apnea, such as daytime sleepiness. However, it didn’t seem to improve the risk of what is often abbreviated as major adverse cardiovascular events (MACE), such as:
- Heart attack
- Hospitalization for heart problems
- Acute coronary syndrome
- Cardiovascular death
- All-cause death
The majority of commenters seems to believe that this study represents the best summation of our knowledge on the effectiveness of CPAP for these problems. This confirms the results of previous studies. Unfortunately, it shows that CPAP, as used in these studies, was not effective. This leaves a major hole in our confidence about treating sleep apnea.
Compliance Is Likely the Problem
Of course, whenever we see that CPAP isn’t effective, we have to wonder whether poor compliance is the reason why CPAP is ineffective. Speaking to Reuters, one of the authors admitted as much, saying, “Good adherence is hard to achieve with current therapeutic options for PAP.”
The fact that this might be the case was hinted by the fact that in studies where subjects used CPAP for at least four hours a night, they received some benefit, although it wasn’t statistically significant.
The problem with CPAP compliance is not just that people aren’t able to comply with the treatment (many studies show that compliance is less than 50%). The problem is also that the compliance standard itself is too low. The current compliance standard says that people should use CPAP for four hours a night on 70% of nights. This means that a person who is sleeping 8 hours a night can be compliant while only using CPAP for 35% of their sleeping hours. However, some studies suggest that CPAP might need to be used for at least six hours a night, and, ideally, we should strive for an all night every night treatment goal.
Oral appliances with computerized trackers show us that, unlike CPAP, they can deliver this high level of compliance. Even using the all night every night standard, compliance for oral appliances may be as high as 84%.
That’s a compliance rate that really could have an impact on heart health!
Is CPAP Over?
Does this new study mean that CPAP is no longer the top treatment for sleep apnea? It certainly doesn’t look good. The article concludes with a recommendation about the use of CPAP:
“Based on the available evidence, it is reasonable to recommend PAP therapy for the improvement of symptoms in patients with obstructive sleep apnea (OSA) but not for protection against vascular disease or death.” Would anyone really want to go through the nuisance of CPAP just for a minor reduction of symptoms? Would insurance companies pay for it?
But many people point out that it’s too early to write off CPAP. An accompanying editorial in JAMA points out that the data isn’t conclusive. This may be the best analysis of available data, but the available data is still too sparse to make a definitive conclusion. The hope is that the data might spur more research into CPAP to make it more effective, which will include making compliance easier for people.
But until that happens, people who are having trouble complying with CPAP or who are doing just the minimum compliance should consider looking for an alternative that they will use more regularly.