Atrial Fibrillation, Warfarin, and Dementia: Is There a Relationship?

You'll have to ask your doctor if your warfarin(rat poison) has anything to do with dementia. 

Atrial Fibrillation, Warfarin, and Dementia: Is There a Relationship?

Authored by 

Mark Munger, PharmD, FCCP, FACC

July 20, 2016

Atrial fibrillation is one of the most common and often difficult cardiovascular arrhythmias to treat. It is increasing in prevalence, projected to affect almost 16 million adults in the United States by 2050.¹ Treatment involves heart rate control, acute anticoagulation to prevent ischemic stroke, reestablishment of normal sinus rhythm, occasionally anti-arrhythmic drugs, and often long-term anticoagulation with a vitamin K antagonist (VKA) or a direct oral anticoagulant (DOAC). With dose-adjusted VKA, time in the therapeutic range (TTR) of an international normalized ratio (INR) maintained between 2 to 3 is correlated with prevention of thromboembolism.¹
Dementia is defined as the diminished memory combined with 1 or more cognitive deficits.  In concert with atrial fibrillation it most often occurs in the elderly, affecting all of a person’s activities of daily living. Because of the similar prevalence with age, researchers have hypothesized that a risk association may be occur.^2-3 Interestingly; the highest relative risk of dementia and AF is found in younger adults.
So what is the potential mechanism that may lead to this association? Perhaps multiple small microemboli or microbleeds may occur that lead to dementia? Thereby, the TTR would be very important to prevent these repetitive small cerebral injuries.
A recent study by investigators at Intermountain Medical Center, in Salt Lake City, Utah, have found that in a population-based, retrospective study of 2,605 adult patients with a CHADS₂ score primarily of 1 to 3 the percent TTR averaged 63.1±21.3 with an INR < 2.0 25.6±17.9%, > 3.0 16.2±13.6%, dementia is not uncommon.⁴ Dementia was diagnosed in 4.2%, senile in 1.4%, vascular in 0.3%, and Alzheimer’s in 2.5%. After adjustment, the percent TTR was associated with dementia risk, <25% (HR) 5.34, P<0.001; 25% to 50% (HR) 4.10, P<0.001, and 51% to 75% (HR) 2.57, P<0.001 versus 75% control value.
These preliminary findings have multifactorial implications. First and most importantly, these findings need to be verified by other population-based studies or by a controlled clinical trial. Second, TTR is increasingly becoming very important, not just above 55% as has been implicated by the RE-LY trial data, but for chronic quality of life. Third, no matter what anticoagulant is chosen, close follow-up of safety and efficacy are paramount. Fourth, this has implications for the need to maintain anticoagulation clinics, even in the era of DOACs where routine monitoring is stated to the main reason to prescribe these agents. Perhaps, more importantly, is the close follow-up to the need for medication adherence, monitoring for even small bleeds in any organ system, and constant patient education for attentive anticoagulation with dose adjustment, when necessary. Another pharmacist call to arms!

Mark A. Munger, PharmD, FCCP, FACC, is a Professor of Pharmacotherapy and Adjunct Professor of Internal Medicine, at the University of Utah, where he also serves as the Associate Dean, Academic Affairs for the College of Pharmacy.

References:
1. Lip GY, Tse HF, Lane DA. Atrial fibrillation. Lancet. 2012;379(9816);648-661.
2. Bunch TJ, Weiss JP, Crandall BG, et al. Atrial fibrillation is independently associated with senile, vascular and Alzheimer’s dementia. Heart Rhythm. 2010;7(4):433-437.
3. Santangeli, P, Di Biase L, Bai R, et al. Atrial fibrillation and the risk of incident dementia: a meta-analysis. Heart Rhythm. 2012;9(11):1761-1768.
4. Jacobs V, Woller SC, Stevens S, et al. Time outside of therapeutic range in atrial fibrillation patients is associated with long-term risk of dementia. Heart Rhythm. 2014; 11(12):2206-2213.

Warfarin-induced skin necrosis within psoriatic plaques

You can check out these other warfarin side effects from taking rat poison. Luckily I had none and was only on it for a couple of months, now I'm on 325 aspirin and don't seem to have the bleeding side effects from that.

• warfarin side effects (31)

 

Warfarin-induced skin necrosis within psoriatic plaques 

Abstract 

A myriad of different phenomena exist in the dermatological literature which are based on the concept of locus minores resistentiae. The most commonly described phenomenon is the Koebner phenomenon, which is classically associated with the emergence of psoriatic lesions post trauma. Warfarin-induced skin necrosis (WISN) is a rare but severe side effect that leads to necrosis of the skin, predominantly on areas with increased subcutaneous fat. The presented case reports on WISN within psoriatic plaques.
Pictures at link.

Um, Excuse Me, Why Did You Stop My Post-Op Anticoagulant?

You probably need to ask your doctor for the evidence-based reason for your changes in anti-coagulation, from rat poison to aspirin, etc.
http://www.medpagetoday.com/Cardiology/CardioBrief/62803?

Cardiology writer learns firsthand about real-world practice

Commonly-used stroke prevention drug may not control blood clotting over long term - Warfarin

So the rat poison may not continue to be effective. What does your doctor think? The operative expectation there is 'think'.
http://www.news-medical.net/news/20160809/Commonly-used-stroke-prevention-drug-may-not-control-blood-clotting-over-long-term.aspx

Warfarin prescribed to prevent strokes in atrial fibrillation may not adequately control blood clotting over the long-term, even when patients have been historically stable on the drug, according to a study from the Duke Clinical Research Institute.
The findings, published Aug. 9 in the Journal of the American Medical Association (JAMA), are based on an 18-month study of 3,749 patients diagnosed with atrial fibrillation, an irregular heart rhythm. The condition is associated with a higher risk of blood clots and stroke, which are avoidable with anticoagulants, a group of drugs that work to thin the blood and prevent clots.
Warfarin, which has an anti-clotting mechanism that targets how the body uses vitamin K, has historically been the only available drug for stroke prevention. However, warfarin can interact negatively with many other drugs and food, and patients on warfarin require regular monitoring.
While costlier than warfarin, non-vitamin K oral anticoagulants (NOACs), which were first approved for use in the United States in 2010, mostly eliminate these drawbacks while often providing similar effectiveness with improved safety.
"For these reasons, the majority of patients who are newly-diagnosed with atrial fibrillation are prescribed NOACs," said Sean Pokorney, M.D., the study's first author and an electrophysiology fellow at the Duke University School of Medicine.
"One of the challenges we face as a health-care community is that there are patients who have been on warfarin for years, and a big question is whether they should be switched to a NOAC," he said.
To consider this question, Pokorney and co-investigators looked at patients from the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation, a database maintained by the Duke Clinical Research Institute. Patients were eligible to participate in the study if they were taking warfarin. Then, researchers focused on a measure of blood thinness called the international normalized ratio (INR).

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For patients on warfarin, INR is typically measured monthly and ideally falls between 2 and 3. During the study's first six months, 968 patients (26 percent of those taking warfarin) had 80 percent or more of their INR values fall in this range and 376 patients (10 percent of warfarin patients) had 100 percent of their INR values fall in this range.
Over an additional 12 months, these patients were monitored and considered "stable" if 80 percent or more of their INR values were between 2 and 3.
Among patients in the 80 percent group, 34 percent remained stable during the subsequent year; Among patents in the 100 percent group, 37 percent had stability over the next year.
"What these results essentially tell us is that patients' past performance on warfarin doesn't predict their future performance," Pokorney said. "Just because patients have done well on warfarin in the past doesn't mean they will continue to do well, and so it does call into question whether it is appropriate to switch them to a NOAC."
The study also found that about a third of patients in both the 80 percent and 100 percent groups had one or more INR values that were well out of the ideal range during the subsequent year. Pokorney said this finding is important because risk of clotting and stroke increases most significantly when INR falls below 1.5 and risk of brain bleeding increases dramatically when INR rises above 4.
"It's not appropriate for every patient to be treated with a NOAC, but this study shows that all patients eligible for a NOAC, even those who have done well on warfarin in the past, should have a shared decision-making conversation with their health-care provider about considering a change," Pokorney said.

Source:

Duke Health

Brain bleed risk from warfarin may be higher than thought

Also known as rat poison.  I  was on this for 6 months and  my ex hated having to haul me in every week to get my blood tested. Luckily I had no side effects, not even purple toe.
http://www.upi.com/Health_News/2016/03/09/Brain-bleed-risk-from-warfarin-may-be-higher-than-thought/8131457553581/
The widely used blood thinner warfarin -- also known as Coumadin -- may raise the risk of severe bleeding inside the skull by much more than previously thought, a new study suggests.
Researchers examined data from nearly 32,000 U.S. veterans, aged 75 and older, with a common heart rhythm disorder called atrial fibrillation. The investigators found that almost one in three suffered an "intracranial" bleed while taking warfarin for the condition.
"Atrial fibrillation ("a-fib") is a common heart rhythm disorder in elderly patients. And in patients with a-fib, treatment with the blood thinner warfarin reduces the risk of stroke by nearly two-thirds," explained study lead author Dr. John Dodson.