Agian
Well-known member
... and this is why you're so meticulous with your INR, and rightly so.
INR range for AVR with On-X
- Thread starter T in YVR
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mike dab
Active member
I just had my AVR wih an On-X valve on Sept 18th. They have me at 2.5-3. I also take the baby aspirin.
In my research of the On-X valve, it is much less "sticky" than other mechanical valves, so my guess is that
you don't need as much anti-coagulation.
From what I can gather, 2.5 seems to be the magic number. Hope that helps.
Just curious, they put a 19mm valve in me. 21 is "average". Are you a pretty big guy with that 25mm valve?
In my research of the On-X valve, it is much less "sticky" than other mechanical valves, so my guess is that
you don't need as much anti-coagulation.
From what I can gather, 2.5 seems to be the magic number. Hope that helps.
Just curious, they put a 19mm valve in me. 21 is "average". Are you a pretty big guy with that 25mm valve?
mike dab
Active member
I was out of range today for the first time (1.8) and they seemed very concerned. They doubled my dose today and doubled it tomorrow, so to answer question number one, my sense is they don't want you out of range at all.
Question number 2 is based on metabolism, but they tell me that it happens pretty quickly. By the time you've digested your food, the vitamin K is in your blood stream and affecting our INR.
I totally agree with how they arbitrarily operate in a vacuum with no knowlege of your eating habits. This is why it takes a lot of adjustment when you start eating your normal diet again at home. It's funny, every time I eat a salad, i too am worried that my INR is going to drop. But they told me today, when it dropped to
1.8, that you'd have nothing but salads for a week to get a drop of .5 or greater. They felt it was more to do with metabolism, the fact that I'm exercising more.
Bottom line--it's been a confusing 6 weeks for me.
Question number 2 is based on metabolism, but they tell me that it happens pretty quickly. By the time you've digested your food, the vitamin K is in your blood stream and affecting our INR.
I totally agree with how they arbitrarily operate in a vacuum with no knowlege of your eating habits. This is why it takes a lot of adjustment when you start eating your normal diet again at home. It's funny, every time I eat a salad, i too am worried that my INR is going to drop. But they told me today, when it dropped to
1.8, that you'd have nothing but salads for a week to get a drop of .5 or greater. They felt it was more to do with metabolism, the fact that I'm exercising more.
Bottom line--it's been a confusing 6 weeks for me.
T in YVR
Well-known member
Hey Mike,
On the valve size question, I am 6'0" and WAS at 200lbs pre surgery. I got down to 180lbs for my surgery (which was my goal) and am now at 174lbs post surgery (and eating alot to try and put some weight back on!). I guess I just have a big heart
I get my INR tested again today, so am very interested to see if I am finally in range (I have been at 1.9 every time I have been tested since Oct. 15). The Dr (my GP) is inching me up VERY slowly to try and get in range. I increased it a bit further on my own and beyond what they required because I think they are off base. We'll know later today. My doctors were not too concerned about 1.9, but I agree with you - I am shooting for 2.5.
One thing I would say is that if they doubled your dose, you might want to watch out for a big jump in INR...that is a big change at 2x. I heard that it can take a few days for the Warfarin to fully kick in and see your INR at its new level (in fact I experienced this at the start of my Warfarin dosing, when I went really high and then fairly low).
Tony
On the valve size question, I am 6'0" and WAS at 200lbs pre surgery. I got down to 180lbs for my surgery (which was my goal) and am now at 174lbs post surgery (and eating alot to try and put some weight back on!). I guess I just have a big heart
I get my INR tested again today, so am very interested to see if I am finally in range (I have been at 1.9 every time I have been tested since Oct. 15). The Dr (my GP) is inching me up VERY slowly to try and get in range. I increased it a bit further on my own and beyond what they required because I think they are off base. We'll know later today. My doctors were not too concerned about 1.9, but I agree with you - I am shooting for 2.5.
One thing I would say is that if they doubled your dose, you might want to watch out for a big jump in INR...that is a big change at 2x. I heard that it can take a few days for the Warfarin to fully kick in and see your INR at its new level (in fact I experienced this at the start of my Warfarin dosing, when I went really high and then fairly low).
Tony
My clinic has told me that metabolism, not diet is the biggest cause of INR changes. The metabolic changes are not fully diet or exercise related and thus not fully predictable, hence the need for routine testing.
My INR dropped with no real change in diet or exercise, but my stress level was pretty high. The clinic said that stress affects the metabolism which can also hit your INR.
When I've been low and joked about eating a salad, they say it wouldn't hurt, but they don't change the dosage based upon diet. They say that unless you are really going at the greens and regularly (e.g. big salad lunch and dinner for a few days in a row, etc.) it doesn't make a big difference.
My INR dropped with no real change in diet or exercise, but my stress level was pretty high. The clinic said that stress affects the metabolism which can also hit your INR.
When I've been low and joked about eating a salad, they say it wouldn't hurt, but they don't change the dosage based upon diet. They say that unless you are really going at the greens and regularly (e.g. big salad lunch and dinner for a few days in a row, etc.) it doesn't make a big difference.
T in YVR
Well-known member
Man, I am getting stressed out trying to get my INR in range since my surgery...I increased my dosage over the past week and saw my INR DROP today from 1.9 to 1.6....I even took more warfarin than my doctor had recommended. My range is supposed to be 2-3. I'm not liking being out of range for 3 weeks now...I feel like I need to give it a good bump up in the dosage. I was doing 6/6/5 and repeating. Then went to 6.5/6/6 (mg). Its a very individual thing, but I can understand what you are saying Tom about exercise and metabolism playing a role. That is the only real significant change I have had in the past 2 weeks or so - much more exercise/walking etc. My diet has been fairly steady. I have added a new heart drug, but doubt that would play a role. Ugh.....I know its not necessarily the case, but I start to feel like I'm a walking time bomb hanging out below range this long.
T
T
You are not a walking time bomb.......you are only 4 weeks post-op and your INR is probably dropping as you exercise more, eat more, etc. As I understand, the ON-X is designed to operate with a lower INR level. My advice is not to make large adjustments as it will cause a YO-YOing INR. After any dosing change, wait a couple days and re-test. Increase your dose by 10-15% until you get well within your 2-3 range. It won't take long to get the hang of it.
T in YVR
Well-known member
Thanks Dick - I'm on pace for about an 11-12% increase this week. I am supposed to test 1 week from now but may go in earlier than this. In the meantime, I'm going to go get my Coaguchek XS this week I think.
Tony
Tony
pellicle
Professional Dingbat, Guru and Merkintologist
Hi
this is a common responce by clinics. I'm unsure there is any validity to it. Neither my surgeon nor my cardiologist were concerned about my range being under as long as it was just dipping there.
Of course knowing that its just dipping there is the reason for weekly testing (and perhaps more frequently when such things take place).
My own experience (and that of many others is would seem) is that such doubling responces by clinics is not needed and often only set up see-saws of your INR: which is rather like watching a kid learning to sail. Steer all over the place trying to keep a straight line.
The solution is easy on the rudder, monitor and let it settle.
For instance: when I found my INR trending down towards 2.2 I took another sample 3 days later (doing what I call "ad hoc monitoring") and see where it goes.
It may just correct back up by itself, and in this instance (as in most others) it has. You can see in this graph that my measurement 1 (which was 21 September 2013) was 2.7 and on the next week (the 29th, point 8 on the chart) it was 2.2 ... I decided to measure again on Tues the 5th Oct and found that with no changes to my dose it had drifted back up to 2.5 (within range)
Should it have stayed low I would have perhaps added 10% to a single dose and gone "meat balls and mash" for a few evenings. Then tested again.
Big changes are unwise and are like tossing big rocks into the waters, ripples move around for a while.
It is the flexibility to measure as you wish (weekly when all is well, ad hoc as needed) that helps you build confidence in what you are doing.
I can understand that feeling ... but don't worry overly and try to take this all in your stride. It does become easier ... I've been there too.
this is a common responce by clinics. I'm unsure there is any validity to it. Neither my surgeon nor my cardiologist were concerned about my range being under as long as it was just dipping there.
Of course knowing that its just dipping there is the reason for weekly testing (and perhaps more frequently when such things take place).
My own experience (and that of many others is would seem) is that such doubling responces by clinics is not needed and often only set up see-saws of your INR: which is rather like watching a kid learning to sail. Steer all over the place trying to keep a straight line.
The solution is easy on the rudder, monitor and let it settle.
For instance: when I found my INR trending down towards 2.2 I took another sample 3 days later (doing what I call "ad hoc monitoring") and see where it goes.
It may just correct back up by itself, and in this instance (as in most others) it has. You can see in this graph that my measurement 1 (which was 21 September 2013) was 2.7 and on the next week (the 29th, point 8 on the chart) it was 2.2 ... I decided to measure again on Tues the 5th Oct and found that with no changes to my dose it had drifted back up to 2.5 (within range)
Should it have stayed low I would have perhaps added 10% to a single dose and gone "meat balls and mash" for a few evenings. Then tested again.
Big changes are unwise and are like tossing big rocks into the waters, ripples move around for a while.
It is the flexibility to measure as you wish (weekly when all is well, ad hoc as needed) that helps you build confidence in what you are doing.
I can understand that feeling ... but don't worry overly and try to take this all in your stride. It does become easier ... I've been there too.
joey66
Member
I have an On-x Aortic valve. I selected that valve specifically to be able to have a more moderated Warfarin dose. My target range is 2-3. I was told as some other that 2.5-3.5 were more typical with other valves. Clinical studies seem to indicate that 2 is the sweet spot to have the lowest combined risk of clot and bleeding. Thus On-X is working to get their valve labeled to recommend 1.5-2.5. Their recently published data seems to support that. Wanting to see more data I like to see my number between 2 and 2.5. Seems like a fair compromise. I did a lot of research on this valve and there are many things about it that make it possible that lower INR targets are a good thing for this valve. In any event, it will be interesting to see how the data develops from the On-X proact trial and future developments.
danjayh
Member
Digging up an old thread here ... but thought I'd post since nobody with a mitral valve had. I have an on-x in the mitral position. Originally my surgeon wanted me to be 2.0-2.5, but at my request he made my 'official' range 2.0-3.0. I check my INR fairly obsessively (at least once a week, more if I'm > 3.0 or < 2.3), and usually try to stay in 2.5-3.0 (I modulate my diet to control it -- that way I'm not 'breaking the rules' by adjusting my own warfarin dose). So far I have had zero problems (my three year surgiversary is in just under a month).
Although testing for the On-X may eventually show that it's safe to have an INR below 2.0, my primary concerns are a) until this is demonstrated, it wouldn't hurt to maintain an INR of 2.0 and higher (2.0-2.5 is a narrow range that may be hard to maintain) and b) not all meters are accurate enough to be comfortable that a 2.0 on the meter is actually a 2.0. (I know -- two years ago I trusted my meter and had a TIA -- a 2.6 on the meter was a 1.7 in the hospital).
There's not much risk of hemorrhagic issues with an INR even into the low-to-mid 3s. (I know, I banged my leg on a leg on the bed last night, and although there was a cut there, I don't have any excessive bruising and the cut bled very little. A cut or injury in an area that has richer blood supply may have produced more blood, but my point is that, even at a 3.4 on my meter (and the hospital said 4.0 on Friday), this was pretty much a non-issue).
There's not much risk of hemorrhagic issues with an INR even into the low-to-mid 3s. (I know, I banged my leg on a leg on the bed last night, and although there was a cut there, I don't have any excessive bruising and the cut bled very little. A cut or injury in an area that has richer blood supply may have produced more blood, but my point is that, even at a 3.4 on my meter (and the hospital said 4.0 on Friday), this was pretty much a non-issue).
pellicle
Professional Dingbat, Guru and Merkintologist
Hi
and for what benefit? None that I know of, but risks are there and well documented.
Those studies (in that metaresearch) suggests that 2 is the lower limit (although there is a 1.9 in there) but please note they are therapeutic range not target value, which both have different methodologies for management of INR.
Dabigatran was tried to get into the valve anticoagulants too ... people died so they stopped the trials. My point is, do you read the brochure from the car company or the reviews from the car magazines?
(hello GM recall anyone?)
between what? From everything I've read the risks of bleeds are for above 3.5 and the risks for thromboembolism below 2. Now the risks are identified, please tell me what it is you gain by being 2 vs 2.5?
wasn't that cancelled?
http://www.valvereplacement.org/for...t-for-Reduced-Anticoagulation-with-On-X-valve
can you name one? I was under the understanding that the target INR was 2.5 (for that valve and other pyrolytic carbon valves such as the ATS/Medtronics) and that 2 was the lower limit. If you try to sit on 2 you will fail and fall under it.
and for what benefit? None that I know of, but risks are there and well documented.
Those studies (in that metaresearch) suggests that 2 is the lower limit (although there is a 1.9 in there) but please note they are therapeutic range not target value, which both have different methodologies for management of INR.
Dabigatran was tried to get into the valve anticoagulants too ... people died so they stopped the trials. My point is, do you read the brochure from the car company or the reviews from the car magazines?
(hello GM recall anyone?)
between what? From everything I've read the risks of bleeds are for above 3.5 and the risks for thromboembolism below 2. Now the risks are identified, please tell me what it is you gain by being 2 vs 2.5?
wasn't that cancelled?
http://www.valvereplacement.org/for...t-for-Reduced-Anticoagulation-with-On-X-valve
One study I like, particularly for the clear graphs in the figure on page 1207 (page 5 of the actual article) is:
Optimal Level of Oral Anticoagulant Therapy for the Prevention of Arterial Thrombosis in Patients
With Mechanical Heart Valve Prostheses, Atrial Fibrillation, or Myocardial Infarction
which can be found online at this link:
http://archinte.jamanetwork.com/article.aspx?articleid=415179 (archinte.jamanetwork.com/article.aspx?articleid=415179)
Although the authors state in the summary that:
The optimal intensity of anticoagulation for patients with mechanical heart valve prostheses was an international normalized ratio (INR) of 2.5 to 2.9;
one can easily see from the graph that the risk profile is very broad and flat, and there is relatively little change between INR of 2.0 and 5.0. Although in this study even at INR=2.0-2.4 the risk is shown to be rising.
This study included many patients with older valve types, and does not separately summarize results for those with mitral versus aortic valve replacements.
Mitral valves typically have greater risk of thromboembolism, so I would expect (just my opinion) the resulting curve would be skewed towards a higher optimum for mitral-valvers. For those with aortic valve replacements, I would expect the curve would be skewed towards the lower optimum.
For newer generation valves, the claim/hope is that the risk of thromboembolism will be shown to be reduced for both aortic and mitral valves, thus enabling the lower knee of the curve to move below INR= 1.5.
As far as I know, the studies on this are still underway for the aortic valve arm of the ON-X PROACT study. I haven't personally seen any results from the mitral valve arm of the study yet. I believe the arm of the study which was cancelled was only the non-warfarin portion.
Optimal Level of Oral Anticoagulant Therapy for the Prevention of Arterial Thrombosis in Patients
With Mechanical Heart Valve Prostheses, Atrial Fibrillation, or Myocardial Infarction
which can be found online at this link:
http://archinte.jamanetwork.com/article.aspx?articleid=415179 (archinte.jamanetwork.com/article.aspx?articleid=415179)
Although the authors state in the summary that:
The optimal intensity of anticoagulation for patients with mechanical heart valve prostheses was an international normalized ratio (INR) of 2.5 to 2.9;
one can easily see from the graph that the risk profile is very broad and flat, and there is relatively little change between INR of 2.0 and 5.0. Although in this study even at INR=2.0-2.4 the risk is shown to be rising.
This study included many patients with older valve types, and does not separately summarize results for those with mitral versus aortic valve replacements.
Mitral valves typically have greater risk of thromboembolism, so I would expect (just my opinion) the resulting curve would be skewed towards a higher optimum for mitral-valvers. For those with aortic valve replacements, I would expect the curve would be skewed towards the lower optimum.
For newer generation valves, the claim/hope is that the risk of thromboembolism will be shown to be reduced for both aortic and mitral valves, thus enabling the lower knee of the curve to move below INR= 1.5.
As far as I know, the studies on this are still underway for the aortic valve arm of the ON-X PROACT study. I haven't personally seen any results from the mitral valve arm of the study yet. I believe the arm of the study which was cancelled was only the non-warfarin portion.
pellicle
Professional Dingbat, Guru and Merkintologist
Hi
interesting study, thanks for posting that
some people just seem unable to design a study, seemingly so intent on randomising things (when they don't quite know the reasons) they'd probably do a study of pregnancy randomizing males and females and note the lower pregnancy rates in males.
Stats is sooooo badly understood. We had a professor during my masters seminar on research methodologies who used to say that it was better to take a "Natural Logarithm" over a "Logarithm to base 10" for presenting log curves of data. I asked him why and he confessed that it was because the graphs looked better to him....
good to know ... thanks
interesting study, thanks for posting that
some people just seem unable to design a study, seemingly so intent on randomising things (when they don't quite know the reasons) they'd probably do a study of pregnancy randomizing males and females and note the lower pregnancy rates in males.
Stats is sooooo badly understood. We had a professor during my masters seminar on research methodologies who used to say that it was better to take a "Natural Logarithm" over a "Logarithm to base 10" for presenting log curves of data. I asked him why and he confessed that it was because the graphs looked better to him....
good to know ... thanks
pellicle
Professional Dingbat, Guru and Merkintologist
Hey, newmitral, a question
looking at this graph (Mech valve is group A)
it seems that they tested a group who were INR 1 ~ 1.4 and another 1.5 ~ 1.9 ... if I'm reading that right 1 ~ 1.4 is essentially "uncoagulated" (not on Anti Coagulation Therapy).
The incidence of an event even in the 1.5~1.9 was 26.6 per 100 patient years.
Shudder.
Yet by moving to 2.0 it dropped 6.7 ... that data speaks for itself to me.
As to the question of the mixture of mitral vs aortic in there I'd stab in the dark and say that the number of mitral valves seems lower than aortic valves, but I can't recally why I think that or if its totally wrong.
Perhaps you could set me straight on that one.
Best Wishes
looking at this graph (Mech valve is group A)
it seems that they tested a group who were INR 1 ~ 1.4 and another 1.5 ~ 1.9 ... if I'm reading that right 1 ~ 1.4 is essentially "uncoagulated" (not on Anti Coagulation Therapy).
The incidence of an event even in the 1.5~1.9 was 26.6 per 100 patient years.
Shudder.
Yet by moving to 2.0 it dropped 6.7 ... that data speaks for itself to me.
As to the question of the mixture of mitral vs aortic in there I'd stab in the dark and say that the number of mitral valves seems lower than aortic valves, but I can't recally why I think that or if its totally wrong.
Perhaps you could set me straight on that one.
Best Wishes
Hi Pellicle
I don't think the authors ever indicated how many of the test subject population had mechanical aortic or mitral valves, they just lumped all mechanical valves together for this study.
Take those high risk numbers for the low INR data points with a grain of salt. As you can see from the table in the figure, they are based on very few patient-years, and the uncertainty bounds around those data points are quite large. I posted some time ago in another thread here:
http://www.valvereplacement.org/forums/showthread.php?40872-Bridge-comadin-for-surgery
giving several references to other studies that show probabilities of major event for uncoagulated patients at "only" about 10%/year, versus the 51.8%/year number shown in this study.
Many of the other studies also show lower overall risks (more like 1% rather than the 2% shown in this study) for patients at their optimum target INR level. Since this study was based on data from 1994 to 1998, it is understandable that the numbers are a bit higher than they would be for a study with only newer, modern design/material valves.
Nevertheless, I like the presentation of the risk profile curves in this study as it is very easy to see how the risk tradeoff between stroke and bleed events leads to the target INR ranges. Seeing the shape of the risk profile, even if the numbers change among studies, gives a good view of the problem.
Trying to stay within the original topic of this thread, I will close by saying that the ON-X folks presumably will come out of the PROACT study with data enabling a similar evaluation, but specific to their valve and valve position (aortic or mitral) which will be the most relevant study for folks like myself who have the ON-X valve.
I don't think the authors ever indicated how many of the test subject population had mechanical aortic or mitral valves, they just lumped all mechanical valves together for this study.
Take those high risk numbers for the low INR data points with a grain of salt. As you can see from the table in the figure, they are based on very few patient-years, and the uncertainty bounds around those data points are quite large. I posted some time ago in another thread here:
http://www.valvereplacement.org/forums/showthread.php?40872-Bridge-comadin-for-surgery
giving several references to other studies that show probabilities of major event for uncoagulated patients at "only" about 10%/year, versus the 51.8%/year number shown in this study.
Many of the other studies also show lower overall risks (more like 1% rather than the 2% shown in this study) for patients at their optimum target INR level. Since this study was based on data from 1994 to 1998, it is understandable that the numbers are a bit higher than they would be for a study with only newer, modern design/material valves.
Nevertheless, I like the presentation of the risk profile curves in this study as it is very easy to see how the risk tradeoff between stroke and bleed events leads to the target INR ranges. Seeing the shape of the risk profile, even if the numbers change among studies, gives a good view of the problem.
Trying to stay within the original topic of this thread, I will close by saying that the ON-X folks presumably will come out of the PROACT study with data enabling a similar evaluation, but specific to their valve and valve position (aortic or mitral) which will be the most relevant study for folks like myself who have the ON-X valve.
joey66
Member
Sorry been away from this thread for awhile. Here is the abstract to the recent publication of the PROACT trial data. No indication of early stoppage of the trial. The first cohort is done and been approved in Europe for lower INR ranges. The other two groups are in process of follow-up. I believe this paper has some references to the 2 INR being the "Sweet spot". Below 1.5 definitely is a risk area. So seems to me to allow for meter error and give you some buffer - 2-2.5 is a great target probably tough to maintain that tight. Going up to 3 for short periods probably not an issue and temporary dips below two above 1.5 also no issue. If you want the whole study, send me a message with an email address and I will send it - or tell me how to attach it here - so far I can't figure that out. I asked the company for the full report and they sent it to me.
http://www.jtcvsonline.org/article/S0022-5223(14)00010-5/abstract
http://www.jtcvsonline.org/article/S0022-5223(14)00010-5/abstract
pellicle
Professional Dingbat, Guru and Merkintologist
Hi
very encouraging. I particularly like the view in the abstract:
To me this suggests (couched in terms of data from other studies on thrombogenesis in valves) that it is quite likely that other bileaflet pyrolytic cabon valves could also perform similarly. For instance this study:
link
I agree entirely with the practical cautions you have put forward. For me this means that I'll keep my target at 2.5 and be less concerned with seeing INR 2 in my self testing data.
Thanks for the information you posted
Best Wishes
very encouraging. I particularly like the view in the abstract:
To me this suggests (couched in terms of data from other studies on thrombogenesis in valves) that it is quite likely that other bileaflet pyrolytic cabon valves could also perform similarly. For instance this study:
link
I agree entirely with the practical cautions you have put forward. For me this means that I'll keep my target at 2.5 and be less concerned with seeing INR 2 in my self testing data.
Thanks for the information you posted
Best Wishes
Heart Of The Sunrise
Well-known member
My cardiologist has me at 2.0 to 2.5.
