CryoLife On-X INR Claims

[Chuck C]

This was published last month: August 2021.

I have found no evidence that the guidelines for mechanical St Jude in the aortic postion have changed. I have been given the range of 2.0-3.0. The below publication is current and recommends a target of 2.5 for St Jude. This would be consistent with the range I was given of 2.0-3.0.

" For patients with an On-X mechanical bileaflet aortic valve with no other risk factors for thromboembolism, we suggest anticoagulation with a VKA to achieve an INR range of 2 to 3 for the first three months after valve surgery; after three months, the goal INR range is 1.5 to 2. "

" For patients with a bileaflet (other than On-X) or single tilting disk mechanical aortic prosthetic valve with no other risk factors for thromboembolism, we recommend anticoagulation with a VKA to achieve a target INR of 2.5. "

" For patients with a mechanical aortic prosthetic valve (other than On-X) and an additional risk factor for thromboembolic events (AF, previous thromboembolism, left ventricular (LV) systolic dysfunction, or hypercoagulable condition) or an older generation mechanical aortic valve prosthesis (eg, ball-in-cage), we suggest anticoagulation with a VKA to achieve an INR of 3. "


https://www.uptodate.com/contents/a...valves in both the aortic,a target INR of 2.5.

 

[Chuck C]

I agree, higher INR, but too late. Now, I have permanent heart damage, and more meds from having a heart attack from the blood clot. They need to do more research with a larger trial. Or just move it to higher 2-2.5.

Hi Bob,

Agan, very sorry to hear about your heart attack.

When you had your heart attack while targeting an INR of 1.5-2.0 with your On-X valve, would you mind sharing if you were on low dose aspirin at the time?

 

[Superman]

Regardless, I think a 0.5 INR window is too narrow and will lead to poor INR management regardless of where you stick the window. Adverse outcomes are at their lowest between 2.0 and 4.0. To me, that’s why 2.5 - 3.5 makes so much sense. A nice wide target leading to more consistent dosing. A 0.5 cushion on either side in case you do fall out of range. I just don’t get the whole, “Lower is better”, mindset.

 

[user 16827]

So is St Jude (now Abbott) also pushing for a lower INR for its valve now? Seeing Leadville's post above made me use 'the Google' -

Not that I am aware of Bill for a mechanical in the Aortic position.

 

[pellicle]

perhaps trying to match the claims of the On-X valve. Interesting times...

Out of interest, what do you see as the advantage of 1.5 over 2?

As I see it we already know that brief dips down to basically un-anticoagulated levels can be done with minimal risks (and still people obsess about bridging). However what is unclear is what effect a strategy of long term lower will do for the build-up of obstruction

Not a long way from 1.5 to 1.2 so make sure you are monitoring weekly and coadministration of aspirin.

We don't have much evidence that 1.5 for years at a time will not lead to such thrombosis obstructions of valve operation.

In the recent past such things led to reoperation, although now it is commonly treated with administration of tPA via a PICC.

This is a multidimensional issue.

 

[BillDaThrill]

Detecting some pushback, let me clarify. I am reporting what the MANUFACTURERS of the valves and the INSTALLER (surgical hospital) are providing as their recommendations and reporting on their websites. I am not providing any recommendation - heck, I've had this ticking valve for a short 3 lovely months today. Yet, I get questioned why I am pushing for lower coagulation numbers - I AM NOT If y'all wanna pick fights with Abbott, Cryolife and the Cleveland Clinic have at it with them. I am just relaying what they are saying. Did I say 'lower is better for INR'? Nope. But my CC surgeon (Svensson) did. But Abbott (provided link on previous post) and Cryolife do on their websites for their aortic mechanical valves. I am fat, dumb and happy with my INR of 2-3 and have no plans to change it, despite both the CC and Cryolife saying I can drop to 1.5 - 2 starting tomorrow. All I am saying is there is a lot out there recommending lower coagulation and studies on-going investigating alternatives. Don't shoot the messenger.

 

[dick0236]

IMO a heart surgeon is one of the worst professionals to ask about INR. In the 54+ years since my heart surgery, I have never seen a SURGEON after leaving the hospital post surgery. Obviously, they prefer not to operate on anyone who has "thin" blood 'cause it makes their job a little more difficult. Ask the doc who monitors your INR for their thought on the proper INR level. I have had many discussions over the years with my Cardio or GP (the docs that actually monitor my INR) about INR dangers. Almost to the man, or woman, my docs agree that the drug is seldom the problem........most problems are non-compliance by the patient. The patients who understand Warfarin and take a role in managing their INR seldom have a problem.

ps; there is no way in hell I would ever let my INR to stay below 2.0........I did it once, a long, long time ago and I have never fully recovered from the STROKE I suffered. I fully subscribe to the saying "blood cells are replaceable, brain cells are not"..........give me a bleed over a stroke anytime!

 

[pellicle]

Detecting some pushback, l

I was just trying to understand if you were merely reporting or also inclined towards that direction (as many are), it was unclear so I asked.

My only pushback is for myself, everyone else can do what they want. I also give reasons for my position. I thought my question (exactly " Out of interest, what do you see as the advantage of 1.5 over 2? " ) was quite plain and simple, not something like:


Why do you interpret discussion as shooting the messenger? I only see people asking general questions and having discussion about the idea.

Yet, I get questioned why I am pushing for lower coagulation numbers -

I'm sorry if you felt that was attacking you

I see questions and I simply asked your position on what you see as the advantage. I did not see anyone say "why do you push for lower INR numbers"

However I received a comment like this which is actually an accusation and false: >> your belief in a higher than recommended INR is a personal risk assessment, not based upon empirical data but what "feels good in your gut. "<< which I responded to.

I see nothing like that in the above discussion directed at you, however I'm sorry if me asking that seems to be attacking you, I'm certainly not.

PS: I saw this post of mine to you as being supportive of your view and expanding on it with data

https://www.valvereplacement.org/threads/cryolife-on-x-inr-claims.888035/post-910549

 

[pellicle]

Please do not construe this as me attacking but instead discussing in good spirit

Man, that sure sounds like they are also pushing for lower coagulation - perhaps trying to match the claims of the On-X valve. Interesting times...

I read that page and found that it mentions that others have done studies (such as the LOWERING IT study). I did not see guidance from them on the INR.

I've mentioned that study quite a bit in the past as a confidence booster to people who newbies and are apparently hyper-anxious about their INR dropping to 1.9 (and will I turn into a clot and die)

I have also discussed it in terms of the On-X protocol, here is one such post
https://www.valvereplacement.org/th...now-if-agree-with-my-plans.887954/post-904010
the Lowering IT study (link) (which was published in 2010) is in my view aimed at assisting people who do have bleeding issues (such as Critter recently mentioned) and they say this in their Abstract:

The primary outcome was assessment of noninferiority of the low over the standard anticoagulation regimen on thromboembolic events. Secondary end point was the superiority of the reduced INR target strategy on bleeding events.​

​

LOWERING-IT trial established that the proposed LOW-INR target is safe and feasible in low-risk patients after bileaflet aortic mechanical valve replacement. It results in similar thrombotic events and in a significant reduction of bleeding occurrence when compared to the conventional anticoagulation regimen.​

So to be clear I see that Abbot are responsibly laying the ground work with data but not issuing any guidance about INR selection.

Their wording about INR was this:

AORTIC ANTICOAGULATION MANAGEMENT
A DEMONSTRATED WORLDWIDE HISTORY OF EXCELLENCE OVER A WIDE INR RANGE
(sorry about the caps its a copy past, I'm not yelling)

They cite studies and I assume its simply reasonable and prudent marketing to associate themselves with this (implying support but not giving it) idea in the face of known market anxiety about low INR.

Again I say I don't feel that for a low risk patient that a transient low INR is harmful but I have questions about long term (decades, which one would rightly expect these valves to last) viability based on what I know. Let me know if you'd like me to clarify that.

Best Wishes

 

[almost_hectic]

If y'all wanna pick fights with Abbott, Cryolife and the Cleveland Clinic have at it with them. I am just relaying what they are saying.

Im not a doctor, scientist, researcher or anything of the like. So for me, any opinions of the above mentioned authorities would suffice. Those are some pretty good names, even if you take Cryolife out of the mix

 

[pellicle]

I did some further reading on their list because of this diagram

I was curious because the Saito study cited did not mention INR levels in the abstract. So I dug in and found the original article (not just the abstract) here: link to full text.

searching for INR within that I found only this:
(bold mine)

With regard to anticoagulation, 5000 units of subcutaneous heparin was started on the first postoperative day and was continued until the prothrombin time or, more recently, the international normalized ratio (INR) was regulated with the administration of warfarin sodium. If the INR was not therapeutic by postoperative day 5, patients would be bridged with a heparin drip until they became therapeutic on oral anticoagulation. Early in our experience, the INR was maintained at 2.5 to 3.5. More recently, we have recommended an INR of 2 for patients who have undergone AVR and 2.0 to 2.5 for MVR; however, Coumadin dosing and INR level were managed by the patient's primary care physician or cardiologist, not the surgeon. Patients were not discharged until their INR was therapeutic. Unless a CABG was performed concurrent with our valve therapy, we did not routinely prescribe antiplatelet therapy upon discharge.​

so I have no idea why Abbot marketing chose to put that 1.6 in there as a lower limit as its not mentioned I can only assume it was conjectured as a range implied by an implication of a target of INR = 2. What is mentioned that I thought noteworthy is bolded.

 

[MdaPA]

As I see it we already know that brief dips down to basically un-anticoagulated levels can be done with minimal risks (and still people obsess about bridging).

pellicle,
How low and for how long is considered minimal risk? And when would bridging be indicated? I understand there are risks associated with bridging and not bridging, but where/what is the risk break-even point if you will?

 

[pellicle]

but where/what is the risk break-even point if you will?

I have no data except the view that short durations for patients described as low risk would seem to be it, and risk is associated with time outside the theraputic window ... Clearly no study has been done so I can only refer to tangential studies

• I cited this one in my blog post on my perioperative INR management that featured in Australian Prescriber . The issue is of course clearly "how long is a piece of string" but when you look at that they provide some level of quantification
  
  I put a red box around my only factor of risk enhancement, of course its impossible to know what the base level or risk was (*but I assume its non zero but small).
• and I often also refer to this study about how long people who have valves have gone with no anticoagulation AT ALL (which I started this thread about some time back)

Again all this is statistical, not certain. So if you roll a dice and the bet is anything greater than 1 you have better odds than a specific number (again, and example).

As well I drew upon @dick0236's example of having a serious thrombosis event after being un-anticagulated for some days and having the higher risk of a first generation valve.

As I wrote in my blog post on perioperative INR management I urge you to read that prescriber article.

I do not advocate you taking risks, I raised the point because if people are apparently happy to have INR below two and also to not take aspirin and further to not check INR weekly (I've seen one such person saying every two weeks is sufficient, or even longer) then you may even be in a sub theraptutic range for a while.

Again, seek details from my blog post on exactly what I mean

I hope that answers your question

 

[MdaPA]

I have no data except the view that short durations for patients described as low risk would seem to be it, and risk is associated with time outside the theraputic window ... Clearly no study has been done

I think the question on "how low can you go" and "for how long" below therapeutic range is certainly is an area of anxiety for folks on anti-coagulation, as like you said, there are no studies/randomized trials.

I hope that answers your question

Yes, it does, thank you.

I do like your quote in one of your blogs, "BUT: Don't **** with this stuff if you don't have a clue. You may get hurt, and that hurt may be permanent. ".

 

[dick0236]

......I do like your quote in one of your blogs, "BUT: Don't **** with this stuff if you don't have a clue. You may get hurt, and that hurt may be permanent. ".

Amen, Amen, Amen to the above quote. Before the introduction of the INR system, I started taking the anti-coagulant Coumadin (Warfarin) after my mechanical valve was implanted in 1967. I was only told to "take the pill and get a blood test monthly" to keep my PT at 1-l/2 times a "normal person"..........and if my urine turned red, to stop taking my pill and get a vitamin K shot. That happened a time or two........but in 1974, I didn't take the pill for 4-5 days while on vacation and that caused a problem much more severe than "red urine'.......I had a STROKE that PERMANENTLY left me 50% BLIND.........so I'll repeat the above quote for emphasis "BUT: Don't **** with this stuff if you don't have a clue. You may get hurt, and that hurt may be permanent". That said, I'm a quick learner, I got a seven-day pillbox and I check my INR routinely........and I haven't had any problems with warfarin since......47 years.

 

[pellicle]

I do like your quote in one of your blogs,

Yep that's exactly how I feel, however I followed that with : »Instead get a clue and start by having a read my other posts on INR management.
«

...and my posts should only be a starter

 

[pellicle]

Thanks for this timely reminder ****

...Before the introduction of the INR system, I started taking the anti-coagulant Coumadin (Warfarin) after my mechanical valve was implanted in 1967. I was only told to "take the pill and get a blood test monthly" to keep my PT at 1-l/2 times a "normal person"..........and if my urine turned red, to stop taking my pill and get a vitamin K shot. That happened a time or two........but in 1974, I didn't take the pill for 4-5 days while on vacation and that caused a problem much more severe than "red urine'.......I had a STROKE that PERMANENTLY left me 50% BLIND.

In general we are very fortunate in the modern world to have:

• a much better studied and more well understood view of warfarin
• better tools to grapple with the problem (such as INR vs Prothrombin Time and,
• better tools such as point of care machines to allow us to live our lives and be free to move around without being tied to a (pick your day/time) weekly blood draw (and the attendant issues such as vascular scarring which that brings).

I want to make it entirely clear here in case people are not taking the framework of my comments into account.

I am NOT advocating anyone miss doses or reduce doses for any other reasons than:

1. the proper maintenance of the appropriate theraputic range that your medical team (and check the fine print, On-X make the same advice) has advised you to be within
2. the management of INR surrounding a procedure in which that medical team has requested your lower your INR.

In that second instance there is discussion around how aggressive bridging should be and what are the risks and benefits. Now in that case its usually unlikely that an INR clinic could be bothered with managing your INR beyond about a weeks window of operation. So they'll advise the following steps:

1. cease warfarin,
2. begin heparin,
3. continue heparin till the day before the procedure,
4. after the procedure commence heparin and also re-commence your dose
5. submit yourself for testing (perhaps a week later) or begin home testing
6. when your INR is in range you may cease heparin bridging therapy

This bridging has been identified as having disadvantages and the word is slowly getting out that a longer gap of completely un-anticoagulated is benefited (again read my blog post above for my dissection of that) before resuming anti-coagulation therapy of any type.

It is from that perspective that I write. None other.

In the "normal" course of events you should maintain your INR within the ranges set.

 

[tom in MO]

Hey Tom, I'm a BAV St Jude guy in the aortic position just like you

I understand your colon point but with regard to the range you cite i am failing to find papers
on this, would you be so kind as to link any, i like to dial into the detail.

my hospital papers show my range 2.5 to 3.5 ( target 3 )

I can find papers on the St Jude at 2 to 3 ( target 2.5 ) in the Aortic position

I have no other factors and aim 2.5 to 3.5 I also do not use ASA

any links would be appreciated , Thanks


EDIT , slight edit to clear up the wording ......

I first heard about it on this forum right before my surgery in late 2011 early 2012. When my range was 2-3 in hospital, I asked my surgeon and he didn't know about the change and told me cardios handle warfarin, not surgeons. I asked my cardio, he said the 2-2.5 range was new and correct but not for me after surgery. It was still 2-3 until things stabilize, around 3 months. It does require 80mg aspirin to be taken daily as well as warfarin.

I'd suggest asking your cardio. I've had two so far and they both use 2-2.5 for my model valve in the aortic position. Your cardio might be at 2-3 for another reason (e.g. aspirin), or do to your specific valve type. Doctors are risk adverse and stick with same-o same-o for reasons like "why change it if it's not broke" just like other people.

When it comes to "published literature" I cannot help you. If you cannot find it with a plebeian search, you might need to use a medical or scientific search engine to find and retrieve it. However, despite people demanding "Show Me the Data" medical research does not have to be published. It only has to be submitted and approved by regulators. I'd ask St. Jude, that may be the quickest route, since it's probably something they want people to know about.

So is St Jude (now Abbott) also pushing for a lower INR for its valve now? Seeing Leadville's post above made me use 'the Google' - and found this page on Abbott's website: Aortic Valve Regent™ Clinical Data | Abbott
The page proudly shows 4 studies whereas SJM valve patients used lower INRs (1.5 - 2.5). Man, that sure sounds like they are also pushing for lower coagulation - perhaps trying to match the claims of the On-X valve. Interesting times...

I know about my valve, and both my cardios say it can readily handle INRs lower than 2 for short periods of time. I have had a surgery on warfarin and was allowed to do it w/o bridging. It did make me nervous since my mil had a stroke due to a lowered INR to replace her valve; so I very well know that your INR is important. She was on warfarin for other problems, and got a tissue valve but had to stay on warfarin.

 

[Warrick]

Before St Jude changed to Abott on their website I recall they did list the range for a St Jude Regent in the aortic position of 2-2.5.
This is about all I can find linked on their site
https://www.structuralheartsolution...lutions/mechanical-heart-valves/clincal-data/

 

[pellicle]

Before St Jude changed to Abott on their website I recall they did list the range for a St Jude Regent in the aortic position of 2-2.5.
This is about all I can find linked on their site
https://www.structuralheartsolution...lutions/mechanical-heart-valves/clincal-data/

But doesn't make a recommendation