Tissue vs. Mechanical

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dick0236

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Depends on how careless you are in managing ACT. I think the 3% is not accurate.....probably closer to 1% and, as sometimes posted on here, it is not cumulative, although it probrably increasess some in "old" age:p.
 
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Mentu

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HH, as you are wading through the confusion of comparing valves, remember that every choice is a compromise; none is perfect for any individual over time. Also keep in mind that few people will die because of their heart valves. As for the 3% increase each year in the chance of stroke with mechanical valves, this would be very difficult to defend. If this were so, almost no one would be using mechanical valves today and the fear of strokes after valve replacement would be a major topic of discussion every day here in VR.ORG. Always run these things by your doctor who should be able to provide you with a better sense of prespective.

Larry
 

markp66

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Lol. I hope not! It's around 1% each year. Well managed ACT makes you have around the same chance of having a stroke as a tissue valve. The difference being that you don't have to worry as much with a tissue valve as you don't take warfarin. The chance of having a stroke increases with older age (as with the normal population). If you go 25 years without having a stroke you probably have the same chance of having a stroke as someone who has just had a new mechanical valve. It's all about well managed ACT.
 

DanielB

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Just got a detailed info packet from On-x and it calls out a 1% risk of stroke, it does not compund as years progress, though, in general, those people over 65 have a higher risk, but that applies to both tissue and mechanical valve receipients.

Dan
 

markp66

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Yeah that's correct for all mech valves especially the on x. It certainly doesn't accumulate and especially not at 3% per year. I still maintain that the 1% also includes people who are off with their INR. Even if in range at their monthly testing there are lots of opportunities to go under/ over in between which is why I think weekly home testing is so important.
 

markp66

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Those figures are pretty encouraging. Hopefully if I need a another valve replacement in the future (I hope i don't) then these figures will be even lower.
 

Lynlw

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chaconne

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1% of those with a mechanical valve have a stroke each year (but don't necessarily die from it?).

If this is true, the risk does accumulate each year, but only for the whole population. In other words, after five years, ~5% of the population will have had strokes. HOWEVER, after 5 years, a bunch of new valve recipients will have entered the population and some of the population will have died of other causes. In other words, it's not all the same people that were in the first year's 1%.

Another thing to realize, is that some of the 1% in one year may end up being the same 1% in the next year (provided the number is not necessarily referring to those who die from a stroke). "Stroke" might be defined as the mildest TIA. Those having strokes are most likely the oldest people and strokes seem most likely to occur in the first few months/year.

All this seems to say that a large % of the MHV population has virtually no chance of having a stroke, provided ACT is properly managed.
 

Greg a

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it's an interesting study but it is just 53 patients who were operated (3rd or 4th OHS) upon from 1985 through 2006 in 1 hospital in Turkey. Alot has changed in OHS from the 80s or even 90s until now.
As usual Lynn you are right on the money and with every day survival rates improve these are stats about strokes in general http://www.theuniversityhospital.com/stroke/stats.htmso manage your ACT and .............. we live in amazing times so Scott, take time every day to cuddle that baby (he'll probably object when he is 65 BUT) I am proud to say that my son (Hannah's dad) gets upset if he is not able to give me a peck on the cheek whenever we part
 

ElectLive

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If you go 25 years without having a stroke you probably have the same chance of having a stroke as someone who has just had a new mechanical valve.
Yes and no. Assuming all other things (valve type and risk factors) being equal, in that particular year, yes both would have comparable risk. This ignores the first 3 months or so of the new valve patient when stroke risk is highest, but that only confuses the issue discussed here, so best to ignore.

Now, on the other hand, the overall probability of having experienced a stroke after 26 years is certainly higher than it would be after only 1 year, and would be true for the ensuing years. But it's not a simple 1%+1%+1% etc calculation either, as has been noted. There's a slightly flawed analogy, but in concept somewhat similar and much easier to understand, so I always relate back to a coin flip, with 50% odds. The probability of turning up at least one heads after two tosses is not 100%, it's 75%, and no matter how many tosses, even though the overall probability of 1 "event" goes up with each toss, it will never reach 100% odds.

Fortunately, valve patients aren't flipping a coin on this. The 1% math is far more favorable. And just because a study of several hundred or several thousand valve patients is able to identify, sum, divide, and caculate into a 1% per patient year stroke risk, that doesn't mean it's an unavoidable law of medicine. If you were to take an equal sample of non valve patients with similar risk factors, the risk per year of stroke would certainly not be 0 either. At the end of the day, stroke risk is very low for us all.
 

pellicle

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Hockey Heart;n40265 said:
Is it true that with a Mechanical Valve, your chance of stroke increases by 3% each year?
no

its not an accumulative thing, just like tossing a coin, because you got a heads does not influence the next toss.
 

LondonAndy

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Perhaps another case of out-of-date information (if it was true at some point)? Good management of Warfarin massively reduces the risks and is easy, thanks to home self-testing with a finger-prick meter such as the CoaguChek XS. Once a week I take a minute or two to check my blood 'thickness' (INR), enabling me to check I am within my therapeutic range and for adjustments to be made if needed. This is now the gold standard of warfarin management in the UK - see this report from our National Institute of Clinical Excellence, that was published in 2014.
 

Protimenow

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Weekly self testing may be the most effective way to prevent thromboembolic events (TIAs or strokes). As mentioned earlier, doctors like to call TIAs - even the most minor ones - strokes.

Even though I was testing regularly, I had a TIA seven or so years ago because I TRUSTED THE WRONG METER. The meter (InRatio, now, fortunately on the scrapheap of medical technology history) was giving me a 2.6. or higher. My actual INR, as tested in the hospital, was 1.7 when I went - two days later - to the E.R.

After returning home (a day or two in the hospital was enough for me), I began a quest to determine the most accurate meter. I tested many meters against each other, and used lab testing to validate the numbers.

My conclusion - CoaguChek XS did a good job, usually a few tenths of a point higher than the lab results (although the higher the INR, to larger the error). This has been well documented.

The Coag-Sense was also very close to the lab results - sometimes showing a prothrombin time that almost exactly matched the lab results - the INR differences were attributable to different reagents used. The Coag-Sense results were often .1 - .3 below the lab results. For me, I prefer a meter whose results are below the lab results because if my meter says 2.0, I don't really have to worry that my INR is BELOW 2.0.

I'm not trying to support any specific meter -- but to help keep stroke risk down, regular (weekly) testing with a meter you can trust (and this includes Roche and Coag-Sense - I haven't tested meters that aren't available outside the U.S.), stroke risks can be kept low.
 

LondonAndy

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Protimenow;n886897 said:
Weekly self testing may be the most effective way to prevent thromboembolic events (TIAs or strokes). As mentioned earlier, doctors like to call TIAs - even the most minor ones - strokes.
I so agree with all of this post. This frequency of testing, made convenient and realistic by having your own meter to do so, should be advertised on big, neon signs in every cardiac ward in my weird fantasy world. Anticoagulation clinics that tell people otherwise are perpetuating their own, financial self interest, not the best interests of the patient, in my opinion; accepting that some much older patients or those with some disabilities might struggle to self test, but for a normal, able-bodied person it is easy. Fortunately I get my test strips free of charge on our NHS, but if I had to pay for them, at around US$4 each, (so costs are about US$4 per week) I would happily do so for the freedom this way of monitoring a crucial aspect of my health makes possible.

I know different people have different experiences, but I find my INR drops significantly when I have a cold, even before I know that I have a cold. And having just started antibiotics today for a skin infection in my leg, I know my INR will rise quite significantly if I don't adjust my dose. So to be able to self-test more frequently for the next week or two will enable me to make some small, temporary adjustments to my dose whilst sitting in my underwear in the comfort of my own home - not a pretty sight, I accept, but illustrates the convenience and medical efficacy .... Testing only monthly runs the risk of missing events like this, or of not being aware of changes for unknown reasons that lead to us needing different dosing.
 
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