HITS and cognitive deficits- valve choice

[Dirk]

Folks,

one problem with mechanical heart valves maybe that they produce HITS "High Intensity Transient Signals" or MES "Microembolic Signals" when the arteries going to brain are measured with a doppler echo.

These signals are possibly due to gas bubbles generated at the mechanical valve due to cavitation.

ATS valves produce less HITS than SJM valves. Medtronic Hall valves produce nearly no HITS, also biological valves do not produce them.

There is no correlation between anticoagulation and HITS rate.

Some studies suggest that they have neurological effects, other studies do not find any relation of neurological symptoms.

The situation is unclear, but it does effect the decision making to take a mechanical or biological valve.

Have you any opinion about the situation?

Here are some links:


http://www.ncbi.nlm.nih.gov:80/entr...eve&db=pubmed&dopt=Abstract&list_uids=9614290


http://www.ncbi.nlm.nih.gov:80/entr...eve&db=pubmed&dopt=Abstract&list_uids=9731602

http://stroke.ahajournals.org/cgi/content/full/29/9/1821


http://www.ncbi.nlm.nih.gov:80/entr...eve&db=pubmed&dopt=Abstract&list_uids=9731593


http://stroke.ahajournals.org/cgi/content/full/29/9/1821

http://www.ncbi.nlm.nih.gov:80/entr...ve&db=pubmed&dopt=Abstract&list_uids=11385377

http://www.ncbi.nlm.nih.gov:80/entr...ve&db=pubmed&dopt=Abstract&list_uids=12694774


http://www.ncbi.nlm.nih.gov:80/entr...ve&db=pubmed&dopt=Abstract&list_uids=12614792


http://www.ncbi.nlm.nih.gov:80/entr...ve&db=pubmed&dopt=Abstract&list_uids=10772054


http://www.ncbi.nlm.nih.gov:80/entr...ve&db=pubmed&dopt=Abstract&list_uids=11145405


http://www.ncbi.nlm.nih.gov:80/entr...ve&db=pubmed&dopt=Abstract&list_uids=10735407

http://www.ncbi.nlm.nih.gov:80/entr...ve&db=pubmed&dopt=Abstract&list_uids=12493511

http://www.ncbi.nlm.nih.gov:80/entr...ve&db=pubmed&dopt=Abstract&list_uids=12865613

http://www.ncbi.nlm.nih.gov:80/entr...ve&db=pubmed&dopt=Abstract&list_uids=12380477


http://www.ncbi.nlm.nih.gov:80/entr...ve&db=pubmed&dopt=Abstract&list_uids=11788250

http://www.ncbi.nlm.nih.gov:80/entr...ve&db=pubmed&dopt=Abstract&list_uids=10393412

http://www.ncbi.nlm.nih.gov:80/entr...eve&db=pubmed&dopt=Abstract&list_uids=9445343


Best greetings


Dirk

 

[Dirk]

Has nobody of you folks a comment on this problem?

Greetings

Dirk

 

[Marguerite53]

Thank you!

Thank you!

Dirk,

Thank you for the very interesting information and all the links!! I will certainly be investigating them as I make my decision for a valve. I'm still in waiting mode so this is very important stuff for me. I will be interested to see how others respond.

Have been leaning toward tissue all along and this certainly helps bolster me along. Usually Bob (tobagotwo) has alot to say. Maybe he just missed the first post, like I did.

Thanks again.

Marguerite

 

[Dirk]

Indeed I would be very happy if we could start a discussion on this topic as it is so far not clear what to conclude from that.

Greetings


Dirk

 

[tobagotwo]

I'm not ignoring you, Dirk. I've just been a little short on time. Your post looks very intriguing.

Best wishes,

 

[Marty]

Dirk, I think I had a cognitive deficit or two post op but eventually was able to go back to work as a radiologist. I think I am better now than I was ten years ago but this might be due to trying harder and studying more. Postop I had some transient double vision. I was referred to a neuro-ophthamologist who over the phone said it sounded like "micro- emboli" to him. He recommended CT,& MRI for starters. I asked him how this would change how I was treated. He said " probably not at all". I decided to do nothing and the episodes became less frequent and I have had none for the last four years.Having said this, I think the published work of Deklunder and associates is one more reason to consider a bioprosthetic valve particularly if you are young, otherwise healthy,don't want to take warfarin, and don't mind the prospect of a repeat operation in 10, 15, or 20 years.

 

[bvdr]

I've not ignored you either, Dirk. I think the whole topic is very interesting and I have read many of those studies. Since I am, however, living every day with a St. Jude Mechanical Mitral valve, I try not to spend too much time dwelling on the possible problems with such a valve. For those still making the decision on what valve to choose, it makes a lot of sense to spend some time evaluating these studies.

Any time something other than the original equipment is put in our bodies the end function is not quite as good as a properly working natual part. Sometimes we talk about valve replacement as if the surgery itself was the problem when it is truly the heart disease that lead to the valve replacement that is the culprit. I still think all our choices are good ones as far a replacement valves go since all of them end up correcting(at least to a certain degree) the disorder that brought us to the table.

 

[Dirk]

Well I think that is a complicated matter!
As you see, also the studies came to different results. It si not easy to distinguish what was biased b the invstigator and which is reality.

That is the problem I am just dealing with.

And the next thing is: What gives less problems: One surgery and the mechancal valve for rest of life? Or a biological valve and at least the problems with the next surgery which is preprogrammed?
Concerning the "deficits", what they might be anyway, the totalt "integral" over the lifespan counts.

Dirk

 

[Mary]

Dirk,
I'm waiting for you and everyone else (but me) to discuss this. It seems to be one more reason that I'm going with tissue, but if I'm wrong, I'm sure someone will let me know.
Don't forget, many people on the forum have had their valve replacements, so some discussions seem rather moot after the fact.
I hope you keep finding the information so it can be viewed and discussed. That's the beauty of this site.
Mary

 

[Mb]

Dear Dirk:

Thank you for bringing up this subject again. I've also posted on it....some time ago, after having done similar searching on the net. It is my firm belief that the cavitation causes many of the problems of the folks on this board....blurred vision, memory issues, short dizzy spells, etc. I think also the silent migraines, or aura's folks talk about could come under the same heading. When I posted a while back, I found little interest as well. I think for those who have the mechanical valves, they probably think there is nothing that can be done about their situation, for those that have tissue valves it does not apply to them, and the symtoms are benign anyway. Personally I disagree. I was thinking that for those folks that have 100+ HITS, a filter could be installed that would break up the gaseuous bubble, before it hit the brain. Then, the long term deficit could be forestalled.

But again, perhaps with folks this ill, these post surgery affects are not important. Not sure. Very good research done by you though! Marybeth

 

[Bryan B]

The bottom line is that if you have a failing valve you have to choose from the available options and make a decision based on what you think is best for your own individual case (and some did not have a choice due to circumstances). After surgery, nothing positive is gained by second guessing yourself (or others).

 

[tobagotwo]

I'm still not ignoring your research, Dirk. I want to post here. I've been investigating the difference between "working" and "episodic" memory so I can make some sense when I do. Looks like the thread may have moved on past that by now, though.

Best wishes,

 

[PapaHappyStar]

I have been talking to friends ( doing bio type research ) about how difficult it is to decipher statistical methods used in medical literature. I wasnt too sure whether I could pass judgement, so I asked them and they think it is a bit iffy too.

Reading this stuff is probably good but I think one needs to read the whole paper instead of just the abstract and understand their assumptions and methods to make sure they are valid or ascertain the extent of their validity. This is not easy, for one because I often lack the knowledge to understand all the issues. I am also cautious about believing numbers without a phenomenological explanation of them ... i.e. if valve A is more likely to cause condition B does the paper provide a clue as to why? Maybe one needs to explore the literature further .... look at citations and references etc ( but then perhaps I should change my dissertation topic )

 

[ar bee]

hmm

hmm

i am with some of you:

extremely careful in interpreting medical research, especially when only reading the abstract.

plus: a lot (not all!!) of med research is based on relatively small sample sizes (there are total >200'000 VR done per year, so what do 165 patients tell us???)

we 'valvers) are all below par and the avr will help getting closer back to par, but nothing is as good as what nature evolutionised

well2all
ar bee

 

[Raverlaw]

...particularly if you are young, otherwise healthy,don't want to take warfarin, and don't mind the prospect of a repeat operation in 10, 15, or 20 years.

I'm the first to acknowledge that my mechanical valve isn't as perfect as a God-given native valve in good shape, but it is one heck of a lot better than my native valve ever was. I had dizziness and auras for years before the surgery, and haven't noticed any increase in those symptoms. My vision was a little blurry right after the surgery but has returned to normal, as a recent eye exam has confirmed.

With even a 2% mortality risk for healthy people facing a second surgery, which may be low depending upon your age and other factors, I thought it best to reduce the chances of a second surgery as much as possible. Others may feel differently, but I sincerely hope I never to have to go through OHS again.

So, I will just continue on ticking, and not worry about micro-emboli or a little cavitation. I pop my dose of rat poison daily, and scratch my scar when it itches. Other than that, I feel "normal," which in my case is better than I have ever felt before the AVR.

 

[tobagotwo]

True, Bill. But the takebacks are the risks associated with Coumadin use, which, in general terms, even the mortality risks with resurgery over the long term.

Then there are the cross-issues. People who have xenograft (biological) valves sometimes have to go on warfarin for atrial or ventricular fibrillation or other problems. Mechanical users sometimes face the dilemna of needing OHS again later for work on their aorta or aortic root, or for a second valve.

To me, it seems the Ross Procedure offers the most potential benefits, if you are a good candidate and don't have heart tissue problems. But many of us find out about our hearts after 50, when we're past the "sweet spot" age. And the RP can sometimes have issues with the pulmonary homograft. And they don't really know until they get there whether you will actually be a good candidate. Still, when it goes well...sweet.

Best wishes,

 

[Mary]

Raise the bar on the age for a Ross, Bob.

I hit 52 the end of May, and the surgeon still indicates that I'm an excellent candidate. It depends on how physically active you've been.
Almost 20 years of daily swimming

has helped me tremendously.
I don't intend to push it past 52 though!

 

[medtronic of borg]

I agree

I agree

very strongly with Bryan after the fact does more harm then good!
Med

 

[tobagotwo]

Ross or not decisions

Ross or not decisions

They've done Ross Procedures successfully on people in their seventies. The fifty years thing is mentioned on several of the sites as a preferred age range. Given your moxie, Mary, I think the age range would be immaterial in your case.

Dirk, I've been over those studies, a couple of which look like duplicates from different sources, and the real common thread was that, even if they were there, the only time they could be tied to any significance was when they remained even when the patient was breathing pure oxygen. That was a very small percent, and there didn't seem to be a reasonable description of "significant" in what was presented in the abstracts. I'm not a statistician, but I don't think it would be enough to turn the decision for me.

Most of the other statistics about valves seem to point to a sweet dilemma: the general odds for long-term survival are about the same for both mechanicals and biologicals, including both warfarin risks and resurgery risks. Barring a wonderful new introduction to the field of available valves, the decision really seems to come down to one of your own personality, with an extra spin from your personal circumstances (work, hobbies, other complicating health issues). Interestingly, the statistics themselves seem to bring the decision largely back to a humanistic level.

Are you willing to take the smaller, daily risks of the vagarities of Coumadin usage to avoid having another Open Heart Surgery? Or are you willing to take the all-at-once risk of a certain second surgery to avoid the discipline and daily risks of Coumadin?

Do you spend time in remote places, where you might not have reasonable access to a hospital? Or greatly enjoy an activity that has a high level of injuries, particularly to the head? Do you have other likely surgeries pending that might increase the risk of warfarin?

Do you believe that you will be capable of dealing with all that goes along with another valve surgery in fifteen to twenty-plus years?

Your thoughts about these and similar questions may turn out to have more meaning for you after the surgery than the statistics surrounding an individual valve. Or you could consider picking the type of valve with your gut, and the specific valve with your head.

Studies have value. However their value is greatest when a clear choice emerges from them. That is not the case for valve types, at this time.

Even a new entry to the valve market is not a reliable answer. St. Jude came out with a valve that had a silver coating on the cuff, to help ward off bacterial endocarditis. It turned out that a good portion of those who received it were not tolerant of it, and valve failures resulted. CryoLife came out with a grow-your-own ("Chia") valve that became your own tissue, and even grew with younger patients. But after successful testing in sheep, it had a dismal success rate in human patients.

I wanted that last valve very badly. To me, that was the valve that would beat even the Ross Procedure. Fortunately, the timing was not right for me to get one.

I don't disagree with looking to studies and statistics for a valve, but suggest that you not neglect the human part of the equation, as that is a part you will also have to live with.

Best wishes,

 

[Mary]

I hate to disturb this thread, but I need to add a note to my last post.
Ross, I'm going to get you!

You know what YOU did!