Typical INR range,

[RunMartin]

I have a 25 mm CarboMedics mechanical aortic valve with an INR range of 2.0 to 3.0
Does this seem a normal range for a mechanical valve in the aortic position and does it differ if it was a mitral valve?

My GP thought the range was typically 3.0 to 4.0. for a mechanical valve.

Thanks
Martin

 

[dick0236]

Most have a "typical" range of 2-3 or 2.5-3.5. The newer valves seem to require a range towards the lower side....maybe 1.5-2. My range has always been 2.5-3.5 for my valve in the aortic position....but occasional readings of around 2 or 4 are of little concern....so long as they don't stay at those levels.

 

[RunMartin]

Thanks Dick, it looks like my GPs thoughts on INR are not quite right

 

[pellicle]

Martin, is the valve in mitral position?


Current thinking for this suggests the following (table taken from 2012 guidelines on the management of valvular heart disease)

11.2.2.2
Target INR In choosinganoptimumtargetINR,oneshouldconsiderpati ent riskfactorsandthethrombogenicityoftheprosthesis,as determinedbyreportedvalvethrombosisratesforthatpro sthesisinrelationtospecificINRlevels(Table20).203, 219Currentlyavailable randomizedtrialscomparingdifferentINRvaluescannotb eused todeterminetargetINRinallsituationsandvariedmethod ologies makethemunsuitableformeta-analysis.220–222 CertaincaveatsapplyinselectingtheoptimumINR: †Prosthesescannotbeconvenientlycategorizedbyba sicd esign (e.g.bileaflet,tiltingdisc,etc.)ordateofintroducti onforthe purposeofdeterminingthrombogenicity. †Formanycurrentlyavailableprostheses—particula rlyn ewly introduceddesigns—thereisinsufficientdataonvalveth rombosisratesatdifferentlevelsofINR,whichwouldothe rwise allowforcategorisation.Untilfurtherdatabecomeavail able, theyshouldbeplacedinthe‘mediumthrombogenicity’ category.

(No idea why it stripped spaces ...)

So you may be in that range, assuming there is more we don't know

PS I just checked your bio and found you have an AVR not mitral (you mentioned mitral in your text)

That table above indicated target INR not range. So for your mechanical aortic valve and no other risk factors your target will be 2.5 this represents a range of about 2 to 3 in the range thinking style.

With target INR the idea is to keep on target without undershoot or overshoot. I aim for 2.5 and my variance is not big. If I may use standard deviation mine is 0.3 when looking at any years data.

 

[RunMartin]

Thanks Pellicle. The GP I saw must have dealt with higher risk patients with older type valves.

 

[pellicle]

Thanks Pellicle. The GP I saw must have dealt with higher risk patients with older type valves.

no worries

yeah, or maybe just "out of touch"

being INR=3 isn't going too cause much trouble, but if you've got a more modern pyrolytic carbon valve then being that high doesn't make much sense (as you probably know anyway).

no way to self manage?

 

[Protimenow]

I have an old (it's been in my chest since 1991) St. Jude (yeah, others have much older valves). My stupid clinic decided that my range should be 2.0 - 3.0. Up until these wizards decided that the range should be so narrow, my other doctors were comfortable with 2.0 - 3.5. Sure, as the INR goes up, the risk of bleeding also increases, but I'm not worried about an INR between 2.0 and 4.0.

It's good to keep it, for my aortic valve, to somewhere between 2.5 and 3.5 (or 3.0, perhaps). I'm much more comfortable above 2.0 than I am anywhere near the bottom of my range.

As some of the veterans of this forum probably know, I have a few different meters, from different manufacturers. I trust that my Coag-Sense is consistently just slightly below the lab.

My CoaguChek always seems to be at, or slightly higher than, the lab. An average of the two is often pretty close to lab results.

So -- in answer to your original question, I'm pretty sure that the range for my St. Jude valve in the aortic position is 2.0-3.5, and I'm most comfortable with it (according to my meter) above 2.2 or 2.3 and below 3.1 or 3.2.


------

On another matter entirely, I want to relate a bad experience with my hospital's anticoagulation lab. I self-test, but go to the lab about once a month, to get a result to compare to my meter. Others, of course, go there for monthly tests because that's the protocol that this stupid clinic implements. Three days ago, I had a blood draw. Two hours later, I did a test at home using my Coag-Sense. The Coag-Sense gave me a 2.7. I was comfortable with that -- I figured that the lab result would be close to 3.0.

This afternoon the stupid clinic called me. They told me that my INR was 3.32. (A year ago, they wouldn't have bothered me because this would have been in their old range definition). This time, they were troubled by it.

The asked the usual questions - diet change, etc. I told them that the day AFTER the blood draw, I had about 1/4 ounce of whiskey. That's all it was.

I was told to skip my dose tonight. It made no sense to me. I tried to explain how wrong this stupid clinic was -- that testing people once a month is of little value because it only takes a week or so with an INR hat is too low for a person to have a stroke. Testing once monthly wouldn't be adequate to detect problems between tests.

They couldn't understand this. I was told to skip a dose today -- because I had 'been drinking.' I told the person that I hadn't been drinking. The 1/4 ounce was consumed the day AFTER the blood draw. I was told to return in two weeks for a new blood draw. DO THEY REALLY THINK THAT the effects of one missed dose today would show up in my INR in TWO WEEKS?

I hope that if you are using an anticoagulation clinic, that your clinic isn't as ignorant as this one.

 

[tom in MO]

From what I read, older mechanical valves are 2-3. Some newer valves, such as my 3 yo St. Jude, were changed to 2-2.5. A few newer valves (or maybe just one) are in the 1.5-2 range.

My coumadin clinic treats my INR the same way if it goes above 2.5 or below 2. For example, results of 1.9 and 2.6 there is no change in warfarin, just test in a week. Due to an antibiotic, my INR recently went to 2.9, I took a one day 1/2 dose, but they wanted me to test in 4 days to make sure it dropped...it did.

 

[big_L]

I seem to get a different answer everytime I ask what my target range should be. The discharge papers from Mayo say 2.5 - 3.0, same as that listed in the graphic posted above. My cardio told me it's 2.0 to 3.0. Frustrating.