Riding the INR roller coaster

[UWMike]

So I'm nearly 3 weeks post-op and starting to get a little anxious about this whole INR management thing. At discharge from hospital they told me that the range I should stick to is 2.5 to 3. At that time I was taking 4mg daily and at my first blood test 5 days after being discharged my INR came back as 3.4. My family doctor seems adamant that an above range INR is potentially more dangerous than one slightly below and has told me that she would like me to get as close to 2.5 as possible and that even if it was a little below at 2.3 or so she would be happy. So at that point she reduced my dose to 3mg daily and my next test 4 days later came back at 1.8. She didn't seem particularly concerned but scheduled another test in 3 days after telling me to take 4mg that day and then 3mg each of the next 2 days. Next INR result was 1.5. This worried me but my doctor, while acknowledging that this was clearly too low, still didn't seem that concerned. I was told that this was just the result of my body 'getting back to normal' and told to go back to taking the 4mg daily with another test scheduled in 3 days. Personally, I felt like that dose was too low but I don't know how I would feel about taking a higher dose than what my doctor recommended. I have a home monitoring kit that I'm still learning to use (already wasted a couple test strips) but I don't know how worried I should be about these recent test results and what my doctor is telling me. Has anyone else heard similar advice; that a lower INR is generally safer than a higher one?

 

[dfelder]

In my opinion, "safer" would be within range. I prefer to run at the high end of my range 3.5- just because you can't replace brain cells. It took me over 6 months to regulate my INR. I went through 3 different doctors until I found one that understood my philosophy. I am in the states though.

 

[dick0236]

These are my thoughts.....

1. 2.5-3.0 is a narrow range and you will probably have some trouble staying within those numbers. 2.0-3.0 or 2.5-3.5, depending on your valve, is a more normal range.

2. Your docs reducing you from 4mg to 3mg was a 25% reduction....and that large of a reduction does not seem warranted to get from 3.4 to around 3-.

3. She is testing too soon after a dosing change and before your body has been able to fully metabalize the warfarin.

4. A lot of doctors share her feeling about keeping INR low. I think some of that feeling comes from dealing with old people on warfarin for a-fib or other blood disorders and the docs are scared to death of a bleed. Remember, only about 15% of people on warfarin are valve patients. Most are seniors that are on the drug and they are much more prone to abnormally bleed.

5. I would be concerened with an INR of 1.5. It may not be critically low, but it sure doesn't leave much margin for error.

6. As you continue to recover and become more active I think you will find that a little more warfarin....not less, will be required to keep you in range.

7. Maybe you should get an opinion from a doctor that is more comfortable dealing with a mechanical valve patient.

 

[Matt C]

Most valves should be 2.5 to 3.5. I was on 6mg comadin daily and then ran high sometimes 3.9 I am currently on 6mg daily except Monday and Friday I take 4mg this has kept me stable for a while now.

 

[ski girl]

I've got a mechanical valve too and I find this INR stuff quite fascinating! I've done a fair bit of googling on it and found that the new generation (bi-leaflet) valves have much better hemodynamics than the older ones - which means less chance of forming a blood clot (*Prosthesis thrombogenicity: low: St Jude Medical, On-X, Carbomedics, Medtronic Hall; medium: bileaflet valves with insufficient data, Bjork-Shiley; high: Lillehei-Kaster, Omniscience, Starr-Edwards. - from http://circ.ahajournals.org/content/119/7/1034.full).

So (and I'm NOT a doctor!) those of us with the newer valves are safer at lower INRs than those with the old ball-and-cage valves.

I still prefer to be on the high side of my range as I'd rather have a bleed than a stroke! But I'd prefer to be dead than to have greatly impaired faculties, so if my INR can't be in-range, I want to have it leaning towards my preferred option.

I should add that I take part in sports where I am likely to get hurt, such as mountain biking - yet I would still choose to have my INR a bit higher than a bit lower. Recently I managed a crack on my head and a badly cut shin and neither caused any issues, which has made me a LOT less concerned about my INR being a bit high

 

[lance]

Mike
Correct me if I'm wrong but didn't you have your valve replaced at Toronto General? Do you have a mechanical one.
Why aren't you being managed by them? IF you are interestd in being managed properly send me a PM and I'll refer you to their clinic where mine has been managed properly since 2004. I report my INR results every week to them via e-mail.
If your doctor isn't particularly concerned by an INR of 1.8 she has proven forever she doesn't know what she's doing.
You are in harm's way so do something about it.
Blood can be replaced--brain cells can't.
As you recover, exercise more and put a greater volume of blood through your liver you will need more warfarin not less because that's where warfarin is metabolized
I'm curious. Who wrote the prescription for your monitor and which one did you get? My two monitors were sourced through TGH and that's where I was trained. It was comforting to have one-on-one training.
When I first started testing many strips were wasted so it's normal.
I'm surprised you haven't asked if it's safe to eat "greens", liver, or drink cranberry juice because your anti-coagulated that's the usual myth perpetrated by ignorant doctors.
Read the "stickies" at the top of the page.

 

[Protimenow]

Being that post-op for that short a period is also a bit worrisome. It's my understanding that you may be more prone to clot formation while the body adapts to the new valve. I, too, would probably want to be at the higher end of range than at the low end.

And, as Dick noted, dropping from 4 mg to 3 mg is a 25% drop - and, to me, that seems to be pretty reckless. You may want to find another doctor with more experience with post valve surgery INR management.

If it was me -- I would try to keep my INR at the high end of range - especially for the first three months post-op, when the risk of clotting is supposed to be higher than the risk after three months.

Don't worry about wasting strips. You'll get the hang of using your meter. (What kind did you get?)

 

[tom in MO]

With my valve, Feb2012 implant, the range is 2.0-2.5. I dropped low for awhile initially, but my cardio said that for my valve, it was not a problem. I dropped as low as 1.6 this summer, but my clinic did not get excited (I was) and did not want me to retest for at least 5 days after changing my dose.

 

[lance]

Tom
You should be excited about a test that low. Hopefully it was back in range within a day or so.
Doctors are afraid of bleeding, patients are afraid of strokes. I wish there was a solution to that philosophy.
Meanwhile be pro-active and stay in range.
If you have your own monitor, volunteer a non anti-coagulated friend and learn where coagulant-free blood tests at.
Do you have an On-X mechanical?

 

[UWMike]

Wow. Thanks for the replies. I've read a fair bit about how Warfarin is metabolized and how Vitamin-K interferes with that. I have been eating a few less "greens" than normal but that's just while I try to get in range to begin with, especially with these recent low test results. @lance, I did indeed have it done at Toronto General (my valve is a St. Jude Medical bi-leaflet valve). I have the CoaguChek XS monitor which I believe my Dad bought (out-of-pocket since I don't have private health insurance and it's not covered by OHIP) online so there was no prescription involved nor did I get any training. After getting frustrated with the test strips I got my dad to try it out and his 'normal' blood resulted in a 1.0 reading on the monitor. I have another blood test scheduled for tomorrow. I understand that it takes a while for the warfarin to take effect but in the hospital they were testing me daily and changing my dose according to those results so I don't really know what to expect in terms of the dose/INR relationship. It would make sense to me as well that as I progress it will take more warfarin to keep me in range so it seems like this doctor is just scared to death of a bleed.

lance, I was unaware of such a clinic for managing INR at Toronto General. I was simply told at discharge to go to my family doctor. Depending on how things go in the next couple of days/weeks I may take you up on that referral.

Thanks everyone.

 

[lance]

Mike,
Keep all your receipts for INR monitoring (monitor, strips and lancettes)--they are tax deductible at 100% at income tax time.
The worst hurdle you will face with INR's is finding "professionals" that know what they're doing. I'm speaking from the experience of three TIA's any one of which could have been permanently disabling. I was very, very lucky they weren't. So I smartened up and sought help. I learned home monitors were available from this web site and when my own PCP refused to write the prescription contacted every hospital performing heart surgery in Ontario. TGH responded within 2 hours offering training. I've never looked back.
INR patients will be given bad advice (just read the posts on here) and you will need to recognize it and defend yourself. I've been there many times. Once an MD in the emergency room tried to tell me to drop warfarin for 3 days and reduce my dose by a further 10%. He never asked why I took it, what my range was nor what dose I took. My range at the time was 3.5 to 4 and the test was 4.2. He'd never heard of home testing and didn't believe me when I told him I did.
INR management is not rocket science so learn all you can. The best advice is eat a balanced diet and dose that diet. You need Vit.K for healthy bones.
While you were hospitalized you were probably on Heparin injections until you were in range.
My INR manager works on the 10th floor at TGH and offered to help anyone who asks.
You're already a patient of TGH so I think you could discuss this with your surgeon.

 

[Protimenow]

It's definitely a good idea to do self-testing - if you can. If you want a professional to tell you what the available dosing charts recommend, you should be able to find a professional who can help.

I had a TIA (not life threatening) even while doing self-testing, because I didn't check my meter's values against a lab. What should have been a 2.7 (on the meter), was a 1.7 at the hospital. Now, I normally subtract .6 or so from my meter's reading, and look for a reported result between 3.1 and 4.1 (which should keep me in my 2.5-3.5 range).

I'm not all that convinced that the anticoagulation clinics are that great an idea. The one I went to (even though I was still doing self-testing) saw two in-range readings, then put me on monthly testing. I do NOT think this is frequent enough.

It's also a bit problematic to trust labs -- one day, I had blood draws from two different labs. One lab (which I trust) reported a 2.95. Another lab, which took blood that was drawn at a clinic and then somehow handled (or not) reported 3.6. The 'doctor' who saw the 3.6 immediately told me to skip a dose ONE DAY a week. I don't consider this to be good advice. She apparently didn't realize that if I skip on a Friday, the results will disappear by Tuesday or Wednesday and, next Thursday and Friday, the INR will be back up to where it was.

It's not always easy to find medical professionals who understand anticoagulation. Self test if you have a machine. Don't overreact to any minor changes in INR, make any changes gradual, trust that your INR will fluctuate day to day, learn about warfarin, and follow dosing charts (or come here with questions), so your management is done accurately and effectively.

At least - this is what I do.

 

[AgilityDog]

What Lance Said. In SPADES.

 

[Bev]

Mike, get a referral to the Thrombosis Clinic @ Hamilton General Hospital. The staff there is amazing and they will assist you in getting your INR in range.

 

[tom in MO]

Lance,

I have a St. Jude mechanical, model 23AGFN-756. My range was back up at the next test. I was worried, but comforted myself with the knowledge that even w/o anticoagulation drugs it was not certain death. For modern valves, I wonder if anyone knows the true risk of no anti-coagulation drugs...who would participate in that clinical trial? The only data I saw was quite old.

I use a Coaguchek XS. My only problem was getting a big enough drop. I learned how to do that within the first few weeks, but did burn two strips per test for awhile.


Tom

 

[lance]

Good morning Tom
There is/was a study undertaken by the manufacturers of the On-X valve to determine whether or not recipients could get by an an aspirin a day or a lower level of warfarin.
One of the reasons I like my XS is the option of applying blood to the side of the strip not dropping it. My skin is very dry in the winter and I have a devilish time getting a big enough drop.

 

[catwoman]

I'm dumbfounded that a doctor would be saying it's better to be under range than a little over range.
Doctors frequently assign a patient a very narrow INR range, and that does create the INR yo-yo.
You must remember that they are not the patient. If you were to ask your doctor if he/she would prefer to risk a stroke due to a clot because of the INR being way too low vs. having to apply a little more pressure to stop a bleeding cut, I'm sure they would opt for the latter. My family doctor & I discussed that one time, and he said he far preferred the latter, did not want a stroke.