ResMed's "failed" trial of ASV machines

[sleepstar]

I always feel uneasy when I see suggestions from people on the forum of what to change someone's BiPAP pressures to

My $50,000's worth... I get a chuckle over comments like the above.

First is the assumption that the titration was some miracle process which nailed what my settings should be with 1/2 of a nights worth of monitoring, all hooked up, uncomfortable in a strange bed etc.. Even at home, I have to look at a number of nights to see if there might be a trend taking place.

I wouldn't set a patients BiPAP machine on anything without consulting a sleep physician.

What sleep physican?

sleepstar has a point, in very limited cases, to wit: if a bilevel is prescribed and tuned *by a competent respiratory therapist* to *treat a specific respiratory issue* such as hypoxia, hypercapnia, copd, restrictive lung disease, then yes, diddling around with the settings can negate the benefits of the therapy, and possibly worse.

however, the vast majority of people here are on bilevel because they grabbed one when they could (me) or it makes them more comfortable (you), or they like to play (pugsy). I don't *think* (for what little that's worth) that diddling with the pressures of a bilevel that was rx'd because the person didn't like the back pressure of cpap and wanted more relief is going to be statistically any more of a life threatening situation than diddling with the pressure of their cpap, or apap.

there *have* been a few people on here that had a bilevel rx'd because of respiratory issues, and I've been REALLY hesitant to even suggest changes with those, for the above reasons...

but, yeah, from what I can tell, reading here, "sleep doctors" don't give a crap about that stuff, in general.

Yes, that is what I am referring to. Not BiPAP for comfort, but BiPAP for hypoxia, hypercapnia, copd etc. I sometimes forget that people can access BiPAP for comfort in America. That just doesn't happen where I am, no way.

It seems so unfortunate to me of all the poor experiences with sleep doctors I hear on this forum. I have to honestly say my experience (even as a patient) was fine. No issues whatsoever.

[Krelvin]

Pretty sure the type of access and experience that I have dealt with related to Sleep Dr's is much more typical can what you are talking about. It is quite possible that someone of the condition that this study was aiming for might have more control and support than a normal patient, but we have users here with COPD for example who are here for the reason they are not getting the support they need either because they can't afford it, or can't get it (same type of Sleep Dr I had).

Forums like this exist because most CPAP users are dumped onto DME's who have poor training, next to no followup and are told that is the way it is. So you either find help from others who have gone through the same issues or end up giving up.

[Darth Lady]

I'm going to ask a really dumb, really basic question here: Why does bilevel (and particuarly ASV) seem to be harder on the heart than, say, straight CPAP? I'm just not getting what dynamic is going on between the various pressure settings and cardiac function.

I've also got a cardiologist and a sleep doc who know about each other but don't talk (that's how it usually goes on this side of the pond, anyway). And problems that go beyond AHI.

Like most people here, I just want to get the best treatment I can get. And while I'm certainly not afraid that Dartha's going to kill me, I'd like to get a better understanding of any strain she might be putting on my system.

[sleepstar]

I'm going to ask a really dumb, really basic question here: Why does bilevel (and particuarly ASV) seem to be harder on the heart than, say, straight CPAP? I'm just not getting what dynamic is going on between the various pressure settings and cardiac function.

I've also got a cardiologist and a sleep doc who know about each other but don't talk (that's how it usually goes on this side of the pond, anyway). And problems that go beyond AHI.

Like most people here, I just want to get the best treatment I can get. And while I'm certainly not afraid that Dartha's going to kill me, I'd like to get a better understanding of any strain she might be putting on my system.

That is definitely not a dumb, basic question. In fact, if I'm understanding all this correctly, we are yet to really know why. It will take analysis of these results from this SERVE-hf study to have more of an idea. Respironics have reported they are working with ResMed for this.

These are some things posted on the AASM website:

Importance of the Ejection Fraction: All patients in the trial had an LVEF ≤ 45%. The SERVE-HF study randomized patients with symptomatic heart failure, who had to have an LVEF ≤ 45%, and who had moderate-to severe central sleep apnea syndrome (AHI>15, >50% of events central in nature, and CAI at least 10) to two care arms: best medical care alone, vs. best medical care plus ASV titrated to minimize the AHI. A post-hoc analysis seems to show worse ASV-associated risk as LVEF declines further below 45%. The trial results do not directly address patients with preserved ejection fractions.

Importance of the Diagnosis: All patients in the SERVE-HF study had central sleep apnea associated with heart failure. These results do not inform us about the effects of ASV on patients with other forms of central sleep apnea syndrome, such as that due to opiates, other medical problems, treatment emergent central sleep apnea, or primary central sleep apnea.


So, unless someone has heart failure with LVEF ≤ 45% and they are using this treatment, I would think it is unhelpful and unreasonable to have any concern.

I'm not sure anyone has any idea yet. It will be very interesting to know why. Perhaps your doctor may be able to give you some answers Darth Lady? I'd be interested to hear if anyone knows.

[palerider]

there's another point about this one study about ASV machines, other than the fact that it was a *small* increase (2.5%, or 16.57 people out of 662.5, so 66.25 vs 49.68 people. (making assumptions on how they split up the group, of course), there's this sage advice:

why you shouldn't trust a single scientific study:
Everything we eat either prevents, or causes cancer... Source

[OKCSleepDoc]

Several points here:

1. Nothing we can do at this point but wait until further analysis is conducted. Until then, BOTH Resmed and Respironics have released statements saying that patients who meet the criteria of the study (LVEF < 45 and primarily CSA with AHI > 15, CA > 10 and more than 50% centrals) who are on ASV should be advised to stop therapy. They could consider continuing, this woudl be a decision between provider and patient, however when the manufacturer themselves is saying to stop, i am not sure who would move to use this at this point in time. Perhaps, just like CanPAP, we will see in post-hoc analysis (Arzt et al. for those interested in looking it up) that those who respond to therapy actually do better than those who do not, but until there is more data, anyone on ASV therapy should follow up with their doctor. Especially if you are on ASV, but may have never had an echo performed, etc.

2. EPAP places additional stress on the heart, which is why those with low EF may suffer more from therapy vs without. This is what we saw in the CANPAP trial where essentially those who had increased mortality on therapy typically died within the first 3 months of treatment. However, if you made it beyond 3 months, responders actually improved with pap therapy.

3. Respironics has a current Heart Failure trial on going as well with their own ASV device. We are not yet sure if their data will reveal the same information, or if it will reveal contrary information. IF it is in line with SERVE-HF then not much we can do as it would be pretty convincing evidence that ASV should not be used in this patient population. If their data shows otherwise, then there will be more discussion to follow.

4. There is a whole section that is going to be devoted to this topic at the upcoming APSS Sleep Meeting, so I am sure there will be more to learn over the coming weeks.

5. In the mean time, the best thing to do would be to follow up with your sleep physician/primary care physician/ whoever prescribed you the ASV device. I wouldn't necessarily return the machine, but maybe it will need to sit on the shelf for a little while until we learn more in the next few weeks.

Again, best advice is to speak to your doctor for now.

[Darth Lady]

Interesting, and unsettling , but why does EPAP put stress on the heart, as opposed to, say, straight CPAP pressure? Is it the variability of it? Would lowering EPAP relieve that? (A retitration suggested that I lower EPAP to 6 and raise PS to 19, but I feel like I'm smothering at 6, so when the DME programmed that in, I pretty quickly changed it back to 10 and 15.)

One reason I ask is that I've had an increasingly irregular heartbeat since starting treatment; it's like a broken egg beater going in there a lot of the time. While I certainly intend to follow that up, I'm just not sure, based on a trial among patients in pretty bad heart failure, that I should be extrapolating from that to start banging on my grouchy cardiologist's door asking whether ASV is doing me in (that's where the sleep doc will send me anyway).

[StephenR]

hi there..

as a new user of ASV, I an finding myself as are any of us I guess, stuck between a rock and a hard place.
I was on CPAP up until last week, felt terrible, this was my second go round on CPAP. I was persuaded to try ASV, and it had been incredible. I
have more energy than I have had for years...

I can however understand how this technology could put more strain on the heart. I feel like the machine is enveloping me
in air. For years I have had shallow breathing, and in the summer a feeling of suffocation, Now I can feel like I can breathe again...
ASV has given me a glimpse of what it was like for me when I was young with young lungs.

I am not panicking about the "failed" test, It was after all on a very small, already quite ill portion of the population, but I am weighing my options as to what I will do if
ASV is taken off the market...I hope there is a rational, calm discussion of this technology soon...

Stephen

[NateS]

I pulled up my "Nuclear Chemical Stress Myocardial Perfusion Study with SPECT" report onscreen, which reported:
"By gated SPECT post infusion global LVEF was normal and was calculated at 66%"
so hopefully I am in the clear with my ASV, but of course I will be calling my heart specialist to get his opinion and advice. Hope he is up to speed on this issue.

Regards, Nate

[palerider]

but I am weighing my options as to what I will do if
ASV is taken off the market...I hope there is a rational, calm discussion of this technology soon...

I wouldn't worry... as you said, it's a very small subset meeting very specific requirements, and, it's *one* study.

the ASV technology does way too much good for way too many more people... but, like everything, it's not for everybody.

[SewTired]

Perhaps my use of the term 'scare' was not the correct one to use. However, this finding doesn't only impact my patients, it also impacts my father. So there's a personal element there. He has heart problems and central sleep apnea and I have been helping him with ASV since I started my career in sleep medicine. So yes, I do feel a little uneasy about the findings.

My late Dad had congestive heart failure, certainly apnea and finally COPD - they bypassed the other machines entirely and stuck him on oxygen. Perhaps you need to have his doctors reassess your father. Maybe he has the wrong therapy now that this information has come out. Has it increased his risk of dying this year? Probably not. As others have mentioned, once you have a collection of such serious problems, your risk of dying this year with no therapies at all is fairly high. While statistically significant, it could also simply mean that the therapy is of no VALUE unless it's only value is that the patient feels better so can do things. The oxygen didn't really help my Dad live longer, but it did enable him to walk, albeit slowly, instead of being pushed in a wheelchair.

[BlackSpinner]

And I need to find the originator of that quote that went "the only way a CPAP machine can hurt you is if it falls on your head".

And it is perfectly valid since you are talking about ASV machines for people with heart failure and Ca's and NOT the run of the mill, middle of the road average cpap/apap user on this board.

[archangle]

There have been a few articles suggesting that frequent hypoxia can cause some changes in blood vessels. Some of these effects may be beneficial, such as larger vessels or new blood vessels.

Some of these articles suggested that hypoxia induced changes in the blood vessels and other changes may have some beneficial effects in terms of cardiac death risk. "Angiogenesis" may be a relevant term. You may suffer less damage from a heart attack, or the changes may make an attack less likely.

I seem to recall a statement somewhere that apnea may actually have some positive effects in terms of certain heart problems. I think in general, the benefits outweigh the downside because apnea affects so many things.

It makes sense in some ways. Fighting against oxygen deprivation is "exercise" in some sense and your body adapts to try and live with it. It makes sense that the adaptations your body makes might have some good effects.

[chunkyfrog]

Two year old thread.

[LSAT]

Our "end-of-alphabet boy" troll has not learned to observe posting dates. Morbius wrote that post over 2 years ago.