Aspirin in conjunction with Warfarin

[longoudey]

Does anyone have any views on taking 75mg Aspirin alongside Warfarin? I have been doing this for a year on the advice of my surgeon (on-x aortic valve, target INR of 2.3). My cardiologist has suggested it may not be needed, although he was relatively relaxed about it. I'm all for taking fewer pills but I'm also keen to do everything possible to reduce the risk of clots.

I have two Saint Jude valves, aortic and mitral. For 19 years, I was told not to take aspirin or Advil with warfarin. During that time, I never had an issue. Then two weeks after my third Pfizer shot I had a stroke. My cardiologist then told me to take a baby aspirin every day. After being on aspirin and warfarin together my body was getting bruises everywhere and I started urinating blood. I quit taking aspirin and the bleeding and bruising resolved.

 

[carolinemc]

Okay, I am a bit confused. Don't we want our INR in a certain range with Warfarin? And if we take an aspirin it further raises the INR., probably out of the range we want to be in. Is aspirin better than Warfarin for anticoagulation? Or is warfarin at the desired range adequate for anticoagulation for a particular valve?

We take aspirin for heart reasons and by direction of the cardio. It does not affect the INR or ProTime at all. Mine get affected by antibiotics when I have an infection or dental work to be premedicated for.

 

[carolinemc]

it depends. The data is unclear.

Some time after I had my OHS my aspirin ran out (75mg as you have) and when I had my next appointment with my surgeon (can't recall if it was 6mths or a year) I asked about it. He barely glanced up and said something nonchalant in the manner of "its up to you if you want to continue with it"

So I stopped.

Some years later I found that I had an occasional "dizzy" spell where I wasn't dizzy if I closed my eyes. I noticed that one eye was not perfectly coordinating with the other. It would clear up after about half an hour. On the off chance it was an indicator of a TIA I decided to start aspirin again (half a 300mg tablet every second day). I reasoned that the half life of aspirin in the body was a few hours and my platelets half life was in the order of a week that this would result in a mix of well formed and "aspirin changed" platelets.

Since I started doing that I don't have those dizzy spells.

However now and then I don't have any aspirin when I'm doing my pills up and for various reasons forget to get the aspirin. A couple of weeks after this I get a repeat of the dizzy spells and I immediately go buy some.

So that's how it is for me ... YMMV

If its not helping then no harm done, but if it is then keep using it.

Best Wishes

When I had second surgery, the cardio then put me on aspirin for three years, after that, he took me off the aspirin. Then when I had my eye stroke in 2018, I was put back on the aspirin. Since I had the eye stroke, I take 81 mg once daily. When I get dizzy, it is from my one of the other meds I take, metformin, when I get up too fast.

 

[MdaPA]

Then two weeks after my third Pfizer shot I had a stroke. My cardiologist then told me to take a baby aspirin every day. After being on aspirin and warfarin together my body was getting bruises everywhere and I started urinating blood. I quit taking aspirin and the bleeding and bruising resolved.

Did you receive clot busting drugs (aka thrombolytic therapy) to dissolve it? A side effect of these drugs is blood in the urine along with bruising. If it indeed was the 81 mg aspirin that caused this, then perhaps you might have had drug-induced platelet dysfunction? What did your doctor say?

 

[pellicle]

Then two weeks after my third Pfizer shot I had a stroke

sadly this is a risk of the drugs

https://www.uptodate.com/contents/covid-19-vaccine-induced-immune-thrombotic-thrombocytopenia-vitt

In late February of 2021, a prothrombotic syndrome was observed in a small number of individuals who received the ChAdOx1 CoV-19 vaccine (AstraZeneca, University of Oxford, and Serum Institute of India), an adenoviral vector-based vaccine. Subsequently, similar findings were observed in a small number of individuals who received the Ad26.COV2.S vaccine (Janssen; Johnson & Johnson), also based on an adenoviral vector. This syndrome has been designated vaccine-induced immune thrombotic thrombocytopenia (VITT). Other terminology is discussed below. (See 'Terminology' below.)​

I hope your team managed you well

as that specific risk is now gone I would hope that if you get any thrombic events (manifest as a TIA) that you'll consider resuming aspirin (or antiplatelet therapy of some kind). At the very least you need to have discussed this with your cardiologist.

 

[longoudey]

Did you receive clot busting drugs (aka thrombolytic therapy) to dissolve it? A side effect of these drugs is blood in the urine along with bruising. If it indeed was the 81 mg aspirin that caused this, then perhaps you might have had drug-induced platelet dysfunction? What did your doctor say?

No I did not, because I’m on warfarin they could not do that.

 

[longoudey]

sadly this is a risk of the drugs

https://www.uptodate.com/contents/covid-19-vaccine-induced-immune-thrombotic-thrombocytopenia-vitt

In late February of 2021, a prothrombotic syndrome was observed in a small number of individuals who received the ChAdOx1 CoV-19 vaccine (AstraZeneca, University of Oxford, and Serum Institute of India), an adenoviral vector-based vaccine. Subsequently, similar findings were observed in a small number of individuals who received the Ad26.COV2.S vaccine (Janssen; Johnson & Johnson), also based on an adenoviral vector. This syndrome has been designated vaccine-induced immune thrombotic thrombocytopenia (VITT). Other terminology is discussed below. (See 'Terminology' below.)​

I hope your team managed you well

as that specific risk is now gone I would hope that if you get any thrombic events (manifest as a TIA) that you'll consider resuming aspirin (or antiplatelet therapy of some kind). At the very least you need to have discussed this with your cardiologist.

My doctor said because of my reaction to aspirin that it would be better to stay off of it. I don’t know if it’s my metabolism but I couldn’t do anything without getting bruised up.

 

[pellicle]

My doctor said because of my reaction to aspirin that it would be better to stay off of it.

I'd ask your Dr if they were aware of the clot issues in that above upToDate aggregation article

 

[Al3x]

Thanks for all your comments, which have been most enlightening. It seems to me that practice seems very varied. As my INR target is at the lower end of the 2s I think I will continue to take Aspirin.

The main long-term risk of Aspirin seems to be stomach ulcers so, provided I don't develop one of those, I think I'm relevant comfortable continuing.

 

[pellicle]

which have been most enlightening

I love it when a discussion gets all sorts of angles and everyone benefits (best of all, the asker!)

 

[MdaPA]

No I did not, because I’m on warfarin they could not do that.

If you don't mind me asking, and perhaps this is a question for another or new thread, but what, if anything, did they give you to treat your stroke besides the aspirin then?

 

[longoudey]

If you don't mind me asking, and perhaps this is a question for another or new thread, but what, if anything, did they give you to treat your stroke besides the aspirin then?

They just monitored me, that was all. It took me about two months to recover with physical therapy and a lot of determination. I had the stroke on 11/26/21 then on 2/6/22 I had a TIA which lasted for five minutes. Since then I have been fine.

 

[Unicusp]

Thanks for all your comments, which have been most enlightening. It seems to me that practice seems very varied. As my INR target is at the lower end of the 2s I think I will continue to take Aspirin.

The main long-term risk of Aspirin seems to be stomach ulcers so, provided I don't develop one of those, I think I'm relevant comfortable continuing.

Not true. That is the purpose of enteric coated 81 mg aspirin. It safely passes through the stomach to dissolve in the small intestine. Has been recommended/prescribed by Doctors for many years as part of a heart healthy diet to lower the risk of heart attack and stroke. Of course, each person should consult with there Doctor first, as many factors are involved. It was recommended to me (by Cardiologist) many years before surgery and when high blood pressure was first detected around age 50.

 

[thomas999]

Your valve is not my valve. Your cardiologist is not mine. My valve is a St. Jude mechanical, aortic position.

You made an errant assumption, that is the same valve I have in my aorta. Although for me, my range is 2.5-3.5. Actually I have an aortic valve prosthesis, meaning I have about 6 in of Dacron mesh in place of the aorta that had an aneurysm. Be careful with your assumptions!

 

[Superman]

First 19 years. No aspirin. Last 13 years (since my second OHS), 81mg aspirin.

Since I take it consistently with my warfarin my warfarin dosing accounts for any impact it may or may not have on my INR. It’s larger random doses (for pain relief) that may interact warfarin dosing.

I did get a graft 13 years ago and it’s also possible that it’s just more recent guidance since my original surgery in 1990.

I guess I don’t worry about small differences. Many of us with the same valve have different therapeutic ranges too. I’ve always been 2.5 - 3.5. Many in here are 2 - 3 or 2 - 2.5.

I don’t think any of this has to be bullseye perfect. I’m guessing I was kept at 2.5-3.5 because that’s where I was for 19 years and what doctor wants to own a change if nothing bad has happened under my current care guidance?

 

[vitdoc]

People come to think that medicine is like engineering. I have many engineers as patients and they often are the most concerned with minor details in their care thinking that we have everything down to a perfect science. Sometimes in reviewing these forums I get the same impression that there is an absolute truth that we need to follow. Not true. We have a wide variety of "studies" that give us some clue to reality but clearly don't give us fine granularity to make precise decisions. People also are not the same. We all have marked variations in our genetics, we are of different ages, we eat differently and we may be sedentary or not. All of this adds to the complex diversity of making recommendations about things like the "best" INR or whether ASA should be used or not and for a myriad of other issues.

Low dose ASA has been championed for years as a good thing due to a potential of a variety of effects. Now some are challenging that idea. Maybe the downside out weigh the upside. How we weigh the upside and downside of things also plays an important role in how we behave.
For example, do you go with an INR that is low with a ON-X valve to avoid bleeding but have a higher risk for stroke or visa versa?
Personally stroke to me is a significantly higher concern than bleeding so I go for an INR of 2.5-3.0 with occasional runs over 3 to 3.5. I don't like going to close to 2 with my St. Jude. Others might feel that they are concerned with bleeding and go for 2-2.5. As long as they know what they are doing so be it.

ASA is an anticoagulant. It inhibits platelet function. An anticoagulant is something that reduces the speed of coagulation not just increases the INR. A simple test often used to determine overall coagulation is the bleeding time. This involves making a cut in the skin and measuring how long it takes for the wound to get dry and stop bleeding. ASA will prolong this as will warfarin. But the INR only measures part of the coagulation process and will not be affected by ASA.
How much risk ASA adds to bleeding when one is on warfarin is hard to quantitate but it does increase the bleeding time. So if one is worried about bleeding while on warfarin than unless there is a good reason to be on ASA or other platelet agents such as Plavix one should avoid them. Right now the "good reason" for ASA is a bit nebulous and I personally don't take it routinely. However if my INR for some reason dips unexpectedly low to around 2 and I am going to do something like bicycling I might pop a 81 mg ASA until my INR gets to where I am more relaxed with it.

I have had transient loss of vision over the years several times due to temporary blockages of a retinal artery. Not a fun thing to have. But I have been very fortunate that these episodes have passed within minutes presumably due to the small embolus breaking up and passing. In those days I was not monitoring my INR and I presumed that maybe I was too low. So we make the best decisions based on incomplete data and a wide variation in individuals that the incomplete data is applied to.

 

[pellicle]

Sometimes in reviewing these forums I get the same impression that there is an absolute truth that we need to follow. Not true. We have a wide variety of "studies" that give us some clue to reality but clearly don't give us fine granularity to make precise decisions.

true, and indeed why I often say "INR is not like measuring a piece of steel"

Medicine is actually more like an art than a science, it does however lean heavily on science (such as molecular biology), but the whole system of our body is very complex and we often have no idea why something works (like paracetamol). The pharmacy industry is filled with examples like amiodarone

Amiodarone was first made in 1961 and came into medical use in 1962 for chest pain believed to be related to the heart. It was pulled from the market in 1967 due to side effects. In 1974 it was found to be useful for arrhythmias and reintroduced. It is on the World Health Organization's List of Essential Medicines.[8] It is available as a generic medication. In 2020, it was the 198th most commonly prescribed medication in the United States, with more than 2 million prescriptions.​

or medicines that were developed for one thing, then found a use in another area entirely. Usually all by trial and error.

I would however say that there are "best practices" but these are often also about psychology (like using a pill box because its more than just a convenience).

All these things should be sets of systems designed to prevent accidents ... like a safety net. They are not the word of God because God never gave us his word (ask a Christian (pick your heretic flavour) or a Jew or an Islamic for what that word is) and usually evolving. So its good to keep up with what is best practice now.

Like medicine most people don't actually care about precision and some people care enough to try to guide the others.

Best Wishes

 

[Critter]

I have to second the pill box because after doing this a couple of years now I often ask myself or my wife “Did I take my pills tonight?”. I don’t think I have dementia yet but you sort of become an automaton going thru the same routines every day. I am a board certified family physician so I think I can comment on the medicine is art since I have been practicing for 32 years and still going pretty strong. Advice is given on individual basis using evidence based studies. Despite using the evidence there is a certain Gestalt about it that is sometimes a ”hunch” and not pure science that drives a decision. Reminds me of when the hairs on back of neck stood up during a night dive at Fiji and there was a white tip shark with back arched was coming from my backside. There is definitely a 6th sense. That’s why Dr. Google sucks. Oh , I don’t like amiodarone, very nasty drug. Would recommend going off of it to my patients and replace with a different anti-arythmic . Causes thyroid disorders and half life is like 53 days.

 

[Unicusp]

true, and indeed why I often say "INR is not like measuring a piece of steel"

Medicine is actually more like an art than a science, it does however lean heavily on science (such as molecular biology), but the whole system of our body is very complex and we often have no idea why something works (like paracetamol). The pharmacy industry is filled with examples like amiodarone

Amiodarone was first made in 1961 and came into medical use in 1962 for chest pain believed to be related to the heart. It was pulled from the market in 1967 due to side effects. In 1974 it was found to be useful for arrhythmias and reintroduced. It is on the World Health Organization's List of Essential Medicines.[8] It is available as a generic medication. In 2020, it was the 198th most commonly prescribed medication in the United States, with more than 2 million prescriptions.​

or medicines that were developed for one thing, then found a use in another area entirely. Usually all by trial and error.

I would however say that there are "best practices" but these are often also about psychology (like using a pill box because its more than just a convenience).

All these things should be sets of systems designed to prevent accidents ... like a safety net. They are not the word of God because God never gave us his word (ask a Christian (pick your heretic flavour) or a Jew or an Islamic for what that word is) and usually evolving. So its good to keep up with what is best practice now.

Like medicine most people don't actually care about precision and some people care enough to try to guide the others.

Best Wishes

Ironic. Another old Wyeth drug resurrected. By the brand name of Cordarone. Was manufactured by Sanofi. And it appears a class action suit is out there.

 

[ATHENS1964]

People come to think that medicine is like engineering. I have many engineers as patients and they often are the most concerned with minor details in their care thinking that we have everything down to a perfect science. Sometimes in reviewing these forums I get the same impression that there is an absolute truth that we need to follow. Not true. We have a wide variety of "studies" that give us some clue to reality but clearly don't give us fine granularity to make precise decisions. People also are not the same. We all have marked variations in our genetics, we are of different ages, we eat differently and we may be sedentary or not. All of this adds to the complex diversity of making recommendations about things like the "best" INR or whether ASA should be used or not and for a myriad of other issues.

Low dose ASA has been championed for years as a good thing due to a potential of a variety of effects. Now some are challenging that idea. Maybe the downside out weigh the upside. How we weigh the upside and downside of things also plays an important role in how we behave.
For example, do you go with an INR that is low with a ON-X valve to avoid bleeding but have a higher risk for stroke or visa versa?
Personally stroke to me is a significantly higher concern than bleeding so I go for an INR of 2.5-3.0 with occasional runs over 3 to 3.5. I don't like going to close to 2 with my St. Jude. Others might feel that they are concerned with bleeding and go for 2-2.5. As long as they know what they are doing so be it.

ASA is an anticoagulant. It inhibits platelet function. An anticoagulant is something that reduces the speed of coagulation not just increases the INR. A simple test often used to determine overall coagulation is the bleeding time. This involves making a cut in the skin and measuring how long it takes for the wound to get dry and stop bleeding. ASA will prolong this as will warfarin. But the INR only measures part of the coagulation process and will not be affected by ASA.
How much risk ASA adds to bleeding when one is on warfarin is hard to quantitate but it does increase the bleeding time. So if one is worried about bleeding while on warfarin than unless there is a good reason to be on ASA or other platelet agents such as Plavix one should avoid them. Right now the "good reason" for ASA is a bit nebulous and I personally don't take it routinely. However if my INR for some reason dips unexpectedly low to around 2 and I am going to do something like bicycling I might pop a 81 mg ASA until my INR gets to where I am more relaxed with it.

I have had transient loss of vision over the years several times due to temporary blockages of a retinal artery. Not a fun thing to have. But I have been very fortunate that these episodes have passed within minutes presumably due to the small embolus breaking up and passing. In those days I was not monitoring my INR and I presumed that maybe I was too low. So we make the best decisions based on incomplete data and a wide variation in individuals that the incomplete data is applied to.

Thank you very much for the scientific knowledge you offer us.
A friend of mine used to say, <<For example, while stitching technique for sutures is an art learned through practice, the knowledge of what happens at the cellular and molecular level in the tissues being stitched arises through science.>>.
and today it happened and I read it here too
https://en.wikipedia.org/wiki/Medicine