Spontaneous subdural hematoma while on Warfarin at INR 3.6?

[Nupur]

Hi folks, I am posting this question for a friend. Her mom has had a mech aortic valve for 10 years, on Warfarin with target INR 2.5-3.5, Recently her Warfarin dosage was increased due to TIA, and a few weeks later she had a spontaneous hematoma. I think she has had a second episode of it as well. In and out of hospital. Re introducing Warfarin. Anyone else faced this? Any advice on what the target range should be or what to watch out for? Also, 3.6 is not that high, is age a factor in risk of bleeding with Warfarin? Thanks in advance!

 

[yotphix]

I'm really curious to see some answers to this question. I recall reading that an INR of less than 5 isn't really dangerous, so a spontaneous bleed at 3.5 is surprising to me.

 

[dick0236]

Also, 3.6 is not that high, !

You are right....an INR of 3.6 is not that high and ordinarily should not cause a bleeding problem.

 

[pellicle]

agreed I also don't think 3.5 is high ... for instance:

indicates that you have to be over 4 to be at risk.

People have these sorts of haematoma who aren't on warfarin. So its a bit like "blaming the dog" when someone on warfarin and warfarin is blamed.

Equally there is a step-up in incident numbers when INR goes over 2.9 (from 2.5 to 5 incidents per 100 patient years) so it could be that having an INR of 3.6 contributed to making it larger.

The problem is we will never likely know.

I would encourage you to get your doctor to do D-dimer tests to check for clot precursors. The reasoning is that if you aren't finding the precursors then you can safely back down the INR a bit and test again. Given that the increase in INR was increased due to a TIA (and was that diagnosed correctly?)

https://en.wikipedia.org/wiki/D-dimer

best wishes

 

[Nupur]

Pellicle, where did you get the chart from? Is there an age factor in this? I guess older people are more at risk of bleeding?
I am not sure how the TIA was diagnosed, must be a CT scan but will ask. Maybe she should stay under 3 to be safe.
Thanks!

 

[dick0236]

........... Is there an age factor in this? I guess older people are more at risk of bleeding?........
Maybe she should stay under 3 to be safe.
Thanks!

I looked at a few medical studies on the internet and their conclusions seems to indicate that warfarin does not play much of a role in major bleeding events such a hematoma in patients under 85. Most of the folks that age are on warfarin for non-valve problems(a-fib). I couldn't find any studies on mechanical valve patients in that age range.

From a personal point of view, I am 80(almost), been on warfarin a long time and have not experienced any issues due to my age, My range is also 2.5-3.5 and I try to stay a little above 3. If your friends mother is 85+ it would be good advice to monitor INR to assure she doesn't slip into a higher range that, along with other senior issues, could cause problems.

 

[pellicle]

Nupur
I got it from this journal article
Optimal Level of Oral Anticoagulant Therapy for the Prevention of Arterial Thrombosis in Patients With Mechanical Heart Valve Prostheses, Atrial Fibrillation, or Myocardial Infarction: A Prospective Study of 4202 Patients

http://archinte.jamanetwork.com/article.aspx?articleid=415179

It is across all patients. I know that as age increases incident of bleed increases. Also unless you are on warfarin and or being managed by a hospital there just isn't data. So there isn't as good a data for the population who are older, may have bleeds go to a ER then go home. Its just not correlated.

What I do see is that warfarin is not linked to precipitating bleeds, only making them more problematic in patients who don't have a well managed INR.

This is why I bang on about weekly testing.