Recent study indicates increased morbidity and VPAP ADAPT SV

[Oldern]

Any comments on study results released at least to medical community, 5/13/15? http://www.aasmnet.org/articles.aspx?id=5562

Increased morbidity from 7.5% to 10% where Cheynes Stokes and Chronic Heart Failure involved. I was informed today by neurologist and DME and am working to get a new machine tomorrow.

Present machine 5 years, VPAP ADAPT ASV
Ernest

[Morbius]

Any comments on study results released at least to medical community, 5/13/15? http://www.aasmnet.org/articles.aspx?id=5562

Increased morbidity from 7.5% to 10% where Cheynes Stokes and Chronic Heart Failure involved. I was informed today by neurologist and DME and am working to get a new machine tomorrow.

Present machine 5 years, VPAP ADAPT ASV
Ernest

What's your EF?

[palerider]

Any comments on study results released at least to medical community, 5/13/15? http://www.aasmnet.org/articles.aspx?id=5562

Increased morbidity from 7.5% to 10% where Cheynes Stokes and Chronic Heart Failure involved. I was informed today by neurologist and DME and am working to get a new machine tomorrow.

Present machine 5 years, VPAP ADAPT ASV
Ernest

old news: viewtopic.php?f=1&t=105666&st=0&sk=t&sd ... e#p1001270

[Oldern]

EF: Approximately 50%, dated 9/20/12. Earlier ECHO mentioned 45%.

[Julie]

Can you get a more up to date EF figure?

[Oldern]

Concerning new EF, I asked Neurologist about getting a new echo performed. He said, not necessary. However, I am certain I will try to get another one very soon.

I made a quick search of the messages thinking there had to be something on this and moved on to the Chat thinking there might be some connection.

Thanks to the person who referenced the older message. I always find what I think is good information here.
Ernest

[icipher]

I skimmed the article and didn't see anything regarding exactly HOW ASV use can increase morbidity.

How the heck can a machine that assists in breathing and sustained oxygen levels increase morbidity?

[jnk]

I skimmed the article and didn't see anything regarding exactly HOW ASV use can increase morbidity.

How the heck can a machine that assists in breathing and sustained oxygen levels increase morbidity?

No one really knows if it does yet. However, there is enough evidence from one study to suggest that just maybe it might possibly for a few, and that is enough in medical science to raise enough of a red flag to impact treatment decisions right away.

The statement made was "evidence suggests such treatment may be harmful for such patients."

As for what makes it possible that ASV may have a negative impact for a few, my understanding (limited though it be) is that ASV can uniquely vary the pressures in the chest in a way that can, in turn, vary how blood moves through the heart, which can be a critically sensitive thing for certain heart patients.

Remember how science works, though. It would be easy for a study to seem to "prove" statistically that pain-killers "cause" headaches, since people with headaches generally take pain-killers. Similarly, if it is the particularly damaged patients who are more likely to be prescribed ASV, naturally people on ASV would be more likely to get worse, speaking strictly statistically. Perhaps people with both significant sleep disturbances and significant heart conditions are more likely to deteriorate quickly than people with only one of those conditions or people with less significant versions of the conditions. Only time will tell what the causation, if there is any, is.

For now, the situation, in my view, is only that the responsible thing to do is to point out the statistical relationship and react to it until the actual mechanisms at play get sorted out in more directly related and structured studies.

I have no medical/scientific training or experience whatsoever, though. At least none that I will admit to without a federal court order.



-jnk

[robysue]

Remember how science works, though. It would be easy for a study to seem to "prove" statistically that pain-killers "cause" headaches, since people with headaches generally take pain-killers.

Actually overuse of pain-killers to treat chronic headache pain has been shown to trigger rebound heachaches in some people. And as someone who has suffered rebound headaches, they're not fun to deal with.

Similarly, if it is the particularly damaged patients who are more likely to be prescribed ASV, naturally people on ASV would be more likely to get worse, speaking strictly statistically. Perhaps people with both significant sleep disturbances and significant heart conditions are more likely to deteriorate quickly than people with only one of those conditions or people with less significant versions of the conditions. Only time will tell what the causation, if there is any, is.

Causation is indeed a different issue than correlation. And it is possible that the correlation in the ASV study is nothing more than a correlation due to the fact that people with both significant sleep disturbances and significant heart conditions are simply more likely to deteriorate quickly than people with only one of these conditions.

Nonetheless, when a well designed study shows a statistically significant increase in mortality risk in a (very) specific group of patients receiving a specific treatment, that warrants caution in prescribing the specific treatment to patients in that specific group.

And this study shows that a specific treatment (ASV) shows a statistically significant increase in mortality when used by patients with a combination of symptomatic congestive heart, a reduced LVEF (LVEF <= 45%), and moderate to severe central sleep apnea. In other words, the people with symptomatic congestive heart failure, a reduced LVEF, and moderate to severe CSA who were randomized into the non-ASV therapy group had fewer deaths in this long term, multi-year study than the folks with symptomatic congestive heart failure, a reduced LVEF, and moderate to severe CSA who were randomized into ASV therapy. The recommendations that patients in this specific group of patients discontinue ASV therapy is based on the fact that ASV significantly increased the risk of mortality in the specific group of patients studied.

The authors of the study are quick to point out that the results cannot be extrapolated to patients not in the target group (patients with a combination of symptomatic congestive heart, a reduced LVEF (LVEF <= 45%), and moderate to severe central sleep apnea. In other words, the study makes no recommendations about whether patients using ASV to treat central or complex sleep apnea who do NOT have symptomatic congestive heart failure OR who have a LVEF > 45% should or should not continue ASV because the results from this study are simply not applicable to people not in the studied group.

[jnk]

Remember how science works, though. It would be easy for a study to seem to "prove" statistically that pain-killers "cause" headaches, since people with headaches generally take pain-killers.

Actually overuse of pain-killers to treat chronic headache pain has been shown to trigger rebound heachaches in some people. And as someone who has suffered rebound headaches, they're not fun to deal with.

Similarly, if it is the particularly damaged patients who are more likely to be prescribed ASV, naturally people on ASV would be more likely to get worse, speaking strictly statistically. Perhaps people with both significant sleep disturbances and significant heart conditions are more likely to deteriorate quickly than people with only one of those conditions or people with less significant versions of the conditions. Only time will tell what the causation, if there is any, is.

Causation is indeed a different issue than correlation. And it is possible that the correlation in the ASV study is nothing more than a correlation due to the fact that people with both significant sleep disturbances and significant heart conditions are simply more likely to deteriorate quickly than people with only one of these conditions.

Nonetheless, when a well designed study shows a statistically significant increase in mortality risk in a (very) specific group of patients receiving a specific treatment, that warrants caution in prescribing the specific treatment to patients in that specific group.

And this study shows that a specific treatment (ASV) shows a statistically significant increase in mortality when used by patients with a combination of symptomatic congestive heart, a reduced LVEF (LVEF <= 45%), and moderate to severe central sleep apnea. In other words, the people with symptomatic congestive heart failure, a reduced LVEF, and moderate to severe CSA who were randomized into the non-ASV therapy group had fewer deaths in this long term, multi-year study than the folks with symptomatic congestive heart failure, a reduced LVEF, and moderate to severe CSA who were randomized into ASV therapy. The recommendations that patients in this specific group of patients discontinue ASV therapy is based on the fact that ASV significantly increased the risk of mortality in the specific group of patients studied.

The authors of the study are quick to point out that the results cannot be extrapolated to patients not in the target group (patients with a combination of symptomatic congestive heart, a reduced LVEF (LVEF <= 45%), and moderate to severe central sleep apnea. In other words, the study makes no recommendations about whether patients using ASV to treat central or complex sleep apnea who do NOT have symptomatic congestive heart failure OR who have a LVEF > 45% should or should not continue ASV because the results from this study are simply not applicable to people not in the studied group.

Thanks, Robysue.

Personally, I fully agree with every word you wrote above. Well said.

And this strikes me as a well-written little summary: http://www.medicaldevice-network.com/ne ... nt-4576815

Some of the statements that jump out at me in that summary:

". . . According to preliminary analysis of data . . . "

"Dr Glenn Richards said: 'We are further analysing the data to understand why this unexpected result was observed in this trial.' "

"The company . . . plans to submit results for publication after further analysis."

I agree wholeheartedly that the finding required immediate change in treatment decision criteria. However, in the overall, I have a hard time putting too much stock long-term in one study, no matter how well-structured it was for what it was looking for (that it didn't find).

Certain variables that may not have been measured may have come into play to make the one group different from the other. For example, just to illustrate, if the group on ASV felt better because of better sleep and higher quality of life, they may, in turn, have pushed themselves by engaging in more strenuous activities. I have no idea if that is so, or if it was measured and accounted for in the randomization, but those are, in my opinion, the sorts of things that are notoriously difficult to measure that can have an unexpected effect on statistics, no matter how well the study was put together on paper. Maybe that's a silly hypothesis, but it is only given by me, a lay person, to illustrate confounding factors that may need to be included in further studies designed to address the specific question that is now directly at hand from the side-finding of the trial.

May they get to the bottom of it quickly. It matters. Until the mechanisms are clear, though, it is all far from settled overall, IMO.

-jeff