Warfarin Withdrawal in Patient’s Awaiting Surgery Increases the Risk for Stroke

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Last April Dr. Adnan I. Qureshi reported on research, at the 67th Annual Meeting of the American Academy of Neurology, that has shown that atrial fibrillation patient’s who are taken off of warfarin for surgical procedures have an increased likelihood of having a stroke.

Subjects included in the analysis had atrial fibrillation plus at least one additional risk factor for stroke or death: age >65 years, systemic hypertension, diabetes, congestive heart failure, transient ischemic attack, prior stroke, left atrium diameter 50+ mm, left ventricular fractional shortening <25%, or left ventricular ejection fraction <40%.

Specifically atrial fibrillation patients who discontinued warfarin for surgical procedures had a 1.1% rate of stroke while atrial fibrillation patients who remained on warfarin had a 0.2% rate of stroke.

Read more here:

Warfarin withdrawal in atrial fibrillation patients awaiting surgery dramatically ups stroke risk

Well, this seems like one of those articles where you read the headline and think, “Duh!” Like the article about how obese children have a higher chance of hypertension – No kidding?

Obviously if you are on a medication, in this case warfarin, to prevent having a stroke, and you stop taking the medication, well, you have an increase likelihood of having a stroke. I think everybody suspected this – but what we see here is that the rate of stroke increases five-fold. Wow – that seems incredible!

This article reinforces my strong belief that strict compliance with taking my medications, especially warfarin, is a good idea!

As far as surgery is concerned, clearly, if you need to have the surgery and you need to go off the warfarin, then so be it. The article didn’t mention anything about bridging with Lovenox. You might want to ask your surgeon about that. And also – consider how important the surgery is to your general health. Is the surgery truly necessary? Is it worth risking a stroke?

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Runners with Atrial Fibrillation – Thinking About Having a Cardioversion? “Look Before You Shock”

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This is, so far, the most discouraging article about atrial fibrillation I have ever read:

Left Atrial Appendage Thrombus When Least Expected: Look Before You Shock, Evaluate Before You Ablate | EP Lab Digest

As a distance runner with atrial fibrillation, who never missed a single dose of my anti-coagulant, and who has already had a blood clot in my left atrial appendage, and has already had a “mini-stroke” – this one leaves me feeling a bit hopeless.

Feel free to read the article; but I will go over a few key points here. One of the dreaded consequences of atrial fibrillation is having a stroke. Because the top chambers of the heart, the atria (plural of atrium) are beating so fast that they are basically just sitting there vibrating, the blood pools and becomes sluggish, and is prone to forming blood clots. Combine this with an enlarged left atrium and the likelihood is even higher. The blood clot forms in a little corner of the heart called the “left atrial appendage” (LAA).

appendage

That’s where I formed a clot. If the blood clot, or a piece of the clot, breaks off it can quickly travel to the brain, get caught and cut off the circulation to part of the brain. This is a type of stroke, and is a huge problem for people with atrial fibrillation.

There are people who like to refer to a stroke as a “brain attack” because that’s what it is – like a heart attack in the brain. And like heart attacks there are big ones and small ones. I had a small one (TIA – tangent ischemia episode) that fortunately only lasted a minute or so. A big stroke, of course, can be fatal.

Important point: if a person is in atrial fibrillation and has blood clot in the LAA, it might be very stable. It might be just sitting there, hanging out, because the atria isn’t doing any beating. Everything is pretty tranquil in there. But then the person has a cardioversion (shock to reset the beating heart) or an ablation and the atrium begins to beat again, the blood starts moving through more quickly – well – now there’s a problem. Now the clot can break loose and BLAM!! – you’ve had a stroke!

The problem: it’s difficult to tell whether or not a patient has a clot prior to having a procedure. A regular echocardiogram doesn’t even show a small clot; there’s not enough detail. The best way to determine if a clot is present is to do a transesophageal echocardiogram (TEE).

teeTransesophageal Echocardiogram

I’ve had three TEEs – it’s not fun – sort of like swallowing a telephone. Thankfully the last two that I had involved an anesthesiologist who put me to sleep for the procedure.

As far as I know it is fairly common to have a TEE prior to having an ablation procedure; but less common before a cardioversion (the shock!), especially for people who presumably have a low risk of a LAA blot clot – like people who are appropriately anti-coagulated, or people who have had atrial fibrillation for less that 48 hours.

In this article five interesting cases are reviewed.

Case #1 – a patient who was effectively anti-coagulated but turned out to have a LAA clot anyway (sounds familiar).

Case #2 – a patient who was actually more anti-coagulated than thought necessary, and was in atrial flutter for less than 48 hours, but turned out to have a LAA clot anyway.

Case #3 – an appropriately anti-coagulated person with a low risk of clot (CHADS2 score=1), but turned out to have a LAA clot anyway.

Cases #4 and #5 were high risk patients who would be expected to have a high risk of a clot. Case #5 actually had three clots in her heart – yikes!

How does all this apply to athletes with atrial fibrillation? Well, apparently healthy, athletic patients, who are appropriately anti-coagulated, and either undergoing a planned or emergency cardioversion, still have a certain risk of having a LAA clot and subsequent stroke.

Should everybody have a TEE before having a cardioversion? Probably not. TEE is expensive, unpleasant, and if anesthesia is involved it basically takes up an entire day out of your schedule. It might be a good idea to talk it over with your cardiologist, however.

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