CPAP- Life or Death or just Quality of Life

[JesseLee]

I fell asleep while driving and broke my neck in the accident. It is life or death to me.

[Timur]

This study was published within a year or so of me starting CPAP and it got me very upset at the time, mainly because I have a family history of heart disease and I'm trying hard to avoid the hand dealt.

CPAP has significantly reduced my resting heart rate, which was too high,  and has eliminated my PVCs  and episodes of random atrial tachycardia which were very scary.  I believe that CPAP has had enormous benefits on my health, including cardio vascular health. 

So I completely agree with the comments here that this study does not tell the full story.

One chart from the study bothers me because from my non-scientific background this forest plot indicates that when actually comparing hours of use, longer CPAP usage yielded no other significant CV benefits for patients during the period under study, except in the category of strokes.   

Figure S4, buried in the supplementary index of the study in the NEJM. . 

[Mogy]

I am no stats guy but it seems to me that before the study they felt that CPAP prevents heart attacks, and this study's main objective was to prove that. They we're surprised when it didn't.

From the study:
"Our original plan was to recruit 5000 patients. In 2012, challenges in achieving recruitment targets prompted us to review the accumulated blinded study data and an updated meta-regression of studies of cardiovascular events and severity of obstructive sleep apnea. The meta-regression showed that cardiovascular risk increased by 25 to 32% for every increase of 10 events per hour in the apnea–hypopnea index (the number of occurrences of apnea or hypopnea per hour of sleep), which was a stronger relationship than we had originally assumed.24 In consideration of this information, together with interim blinded trial data showing an annual event rate of 6.86% and better-than-expected adherence to CPAP therapy, we revised our sample size to 2500 patients; we estimated that with this sample size, the study would have 90% statistical power (at an alpha level of 0.05) to detect a 25% lower incidence with CPAP plus usual care than with usual care alone of the primary composite cardiovascular end point, which was anticipated to occur in 533 patients overall over a mean follow-up of 4.5 years."

[Timur]

I remember when the study results were released at a large cardiology conference in Europe in August 2016. I was so interested in this study that I streamed the conference results being discussed by Dr McEvoy who led the study.

Honestly, he looked absolutely crestfallen reporting these outcomes. For sure the researchers were blindsided. 

I read up on the team who were involved in this study and they are ardent supporters of CPAP and very involved in OSA research, some of the most prominent names in Australian sleep apnea research. 

I agree Mogy, this study had anticipated the opposite outcome and I suspect the researchers were as let down and perplexed by these results as all of us are. I am hoping that subsequent studies can address the adherence issue more fully.

[Reznik]

I'm a big believer in science.  Science tells us there is a correlation between sleep apnea, heart disease, and heart attack risk.  

That doesn't mean that sleep apnea causes heart disease and heart attacks.  It could be just the opposite.  Sleep apnea could be an early symptoms of heart disease.  Or some fourth thing could cause all three.