Nav: Home

Medication adherence a problem in atrial fibrillation patients

January 04, 2017

For patients with atrial fibrillation, the most common form of heart arrhythmia, a main goal of treatment is stroke prevention.

Which is why most Afib patients are prescribed a blood thinner such as warfarin, also known by the brand name Coumadin, to combat the potential for blood clots that could lead to stroke.

But warfarin is tough to manage, and some patients have trouble adhering to any medication.

A new research letter published in JAMA Cardiology finds Afib patients are even more likely to discontinue warfarin therapy if they've had a recent procedure done to address their arrhythmia.

"We don't know if changing the heart to a normal rhythm, by either cardioversion or ablation, always removes the risk of stroke," says Geoffrey Barnes, M.D., M.Sc., one of the University of Michigan researchers and a cardiologist at the U-M Frankel Cardiovascular Center. "It's an ongoing debate, whether to continue the patient on blood thinners after a procedure."

Afib procedures as predictors of warfarin discontinuation

Researchers from U-M and other institutions that are part of the Michigan Anticoagulation Quality Improvement Initiative analyzed 734 Afib patients across the state who started warfarin therapy between 2011 and 2013.

The researchers found 36.8 percent of subjects were off warfarin within one year of starting it.

"When we took into account whether the patient had undergone a recent Afib procedure, the numbers look very different," says James Froehlich, M.D., M.P.H., also a researcher with the collaborative and a Frankel center cardiologist. "This may or may not be good news, because when someone's had a recent procedure, there may be good reason to interrupt anticoagulant therapy."

When either electrical cardioversion or radiofrequency ablation was performed, more than half of subjects (54.1 percent) were not on warfarin after a year. Electrical cardioversion shocks the heart back into a regular rhythm. Radiofrequency ablation scars the damaged parts of the heart to prevent the dangerous rhythm.

Subjects who did not undergo an Afib procedure were much more likely to continue warfarin therapy, with less than one-third (29.5 percent) discontinuing it.

Although the numbers are much higher for those who underwent a procedure, 29.5 percent is still a sizable proportion of Afib patients discontinuing warfarin therapy, Barnes says. Reasons may vary, from advice from a physician to side effects such as bruising or a patient's desire to avoid having blood drawn.

"We need to understand why they are stopping warfarin and figure out what other medications might be better adhered to in order to prevent strokes," Froehlich says.

A need for consensus

"Once someone has Afib, we don't yet know when it is safe to stop anticoagulation therapy," Froehlich says.

Yet every day, cardiologists must make recommendations to their patients with the condition.

"We need more data to help us understand what the risk of stroke is after cardioversion or ablation, to inform physician decision-making and guidelines," Barnes says.

In the past couple of decades, it was typical to stop anticoagulants after a patient underwent cardioversion, Froehlich says, but new data are needed -- along with more data about ablation.

The facts from the anticoagulation collaborative allowed the researchers to identify practice patterns statewide, working toward improving the care of patients across Michigan who are taking anticoagulants.
-end-
Funding: The Michigan Anticoagulation Quality Improvement Initiative is funded by Blue Cross Blue Shield of Michigan.

Disclosure: Barnes received research support from Bristol-Myers Squibb/Pfizer and the National Heart, Lung, and Blood Institute (grant T32-HL007853) and consulting fees from Portola and Aralez.

Froehlich received consulting fees from Merck, Bristol-Myers Squibb, Pfizer, Sanofi-Aventis and Janssen and grants from Bristol-Myers Squibb/Pfizer.

Co-author Scott Kaatz, D.O., M.Sc., received consulting fees from Boehringer Ingelheim, Janssen, Daiichi Sankyo, Bristol-Myers Squibb and Pfizer and served on the speaker's bureau for Janssen, Boehringer Ingelheim, Bristol-Myers Squibb, Pfizer and CSL Behring.

University of Michigan Health System

Related Stroke Articles:

Retraining the brain to see after stroke
A new study out today in Neurology, provides the first evidence that rigorous visual training restores rudimentary sight in patients who went partially blind after suffering a stroke, while patients who did not train continued to get progressively worse.
Catheter ablations reduce risks of stroke in heart patients with stroke history, study finds
Atrial fibrillation patients with a prior history of stroke who undergo catheter ablation to treat the abnormal heart rhythm lower their long-term risk of a recurrent stroke by 50 percent, according to new research from the Intermountain Medical Center Heart Institute.
Imaging stroke risk in 4-D
A new MRI technique developed at Northwestern University detects blood flow velocity to identify who is most at risk for stroke, so they can be treated accordingly.
Biomarkers may help better predict who will have a stroke
People with high levels of four biomarkers in the blood may be more likely to develop a stroke than people with low levels of the biomarkers, according to a study published in the Aug.
Pre-stroke risk factors influence long-term future stroke, dementia risk
If you had heart disease risk factors, such as high blood pressure, before your first stoke, your risk of suffering subsequent strokes and dementia long after your initial stroke may be higher.
Intervention methods of stroke need to focus on prevention for blacks to reduce stroke mortality
Blacks are four times more likely than their white counterparts to die from stroke at age 45.
Study shows area undamaged by stroke remains so, regardless of time stroke is left untreated
A study led by Achala Vagal, M.D., associate professor at the University of Cincinnati College of Medicine and a UC Health radiologist, looked at a group of untreated acute stroke patients and found that there was no evidence of time dependence on damage outcomes for the penumbra, or tissue that is at risk of progressing to dead tissue but is still salvageable if blood flow is returned in a stroke, but rather an association with collateral flow -- or rerouting of blood through clear vessels.
Immediate aspirin after mini-stroke substantially reduces risk of major stroke
Using aspirin urgently could substantially reduce the risk of major strokes in patients who have minor 'warning' events.
SAGE launches the European Stroke Journal with the European Stroke Organisation
SAGE, a world leading independent and academic publisher, is delighted to announce the launch of the European Stroke Journal, the flagship journal of the European Stroke Organisation.
The S-stroke or I-stroke?
The year 2016 is an Olympic year. Developments in high-performance swimwear for swimming continue to advance, along with other areas of scientific research.

Related Stroke Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Jumpstarting Creativity
Our greatest breakthroughs and triumphs have one thing in common: creativity. But how do you ignite it? And how do you rekindle it? This hour, TED speakers explore ideas on jumpstarting creativity. Guests include economist Tim Harford, producer Helen Marriage, artificial intelligence researcher Steve Engels, and behavioral scientist Marily Oppezzo.
Now Playing: Science for the People

#524 The Human Network
What does a network of humans look like and how does it work? How does information spread? How do decisions and opinions spread? What gets distorted as it moves through the network and why? This week we dig into the ins and outs of human networks with Matthew Jackson, Professor of Economics at Stanford University and author of the book "The Human Network: How Your Social Position Determines Your Power, Beliefs, and Behaviours".