Medication adherence a problem in atrial fibrillation patients

January 4, 2017
Anticoagulant therapy is important for stroke prevention in people with atrial fibrillation, but a new study shows many people don't stick with it. Credit: University of Michigan Health System

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 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 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.

Explore further: Surgical ablation found to be effective in reducing atrial fibrillation and improving quality of life

More information: "Discontinuation of Warfarin Therapy for Patients With Atrial Fibrillation," JAMA Cardiology DOI: 10.1001/jamacardio.2016.5041

Related Stories

Surgical ablation found to be effective in reducing atrial fibrillation and improving quality of life

December 19, 2016
New clinical practice guidelines have been issued by The Society of Thoracic Surgeons (STS) that include major recommendations for the use of surgical ablation when treating atrial fibrillation (Afib), the most common type ...

Atrial fibrillation patients are at increased risk of dementia, regardless of anticoagulation use

November 15, 2016
Atrial fibrillation patients who use the drug, warfarin, to prevent harmful blood clots from forming in their hearts to lower risk of stroke are at higher risk of developing dementia than patients who use warfarin for non-atrial ...

Safer drug combination found for patients with high-risk atrial fibrillation

March 6, 2015
Patients with high-risk atrial fibrillation, or AFib, often require one drug to regulate heart rhythm and a second drug to thin their blood and reduce the risk of stroke. A recent study led by a University of Missouri School ...

Trial results for anticoagulants for cardioversion in AF patients published

August 30, 2016
The results of the largest known clinical trial to investigate the use of anticoagulants prior and post cardioversion in atrial fibrillation patients, published in The Lancet, show that non-vitamin K antagonist oral anticoagulants ...

Rate, rhythm control equally effective in post-operative atrial fibrillation

April 4, 2016
In the first large randomized trial to directly compare two approaches to preventing a type of abnormal heart rhythm that is the most common complication of heart surgery, the two strategies—controlling heart rate and controlling ...

Dabigatran superior to warfarin when anticoagulation is resumed after bleeding

December 1, 2016
In the first analysis of how to treat patients on anticoagulants who suffer a major bleeding event, a clinical practice that routinely gives doctors pause, while also evaluating a new drug, University of Pittsburgh researchers ...

Recommended for you

Could aggressive blood pressure treatments lead to kidney damage?

July 18, 2017
Aggressive combination treatments for high blood pressure that are intended to protect the kidneys may actually be damaging the organs, new research from the University of Virginia School of Medicine suggests.

Quantifying effectiveness of treatment for irregular heartbeat

July 17, 2017
In a small proof-of-concept study, researchers at Johns Hopkins report a complex mathematical method to measure electrical communications within the heart can successfully predict the effectiveness of catheter ablation, the ...

Concerns over side effects of statins stopping stroke survivors taking medication

July 17, 2017
Negative media coverage of the side effects associated with taking statins, and patients' own experiences of taking the drugs, are among the reasons cited by stroke survivors and their carers for stopping taking potentially ...

Study discovers anticoagulant drugs are being prescribed against safety advice

July 17, 2017
A study by researchers at the University of Birmingham has shown that GPs are prescribing anticoagulants to patients with an irregular heartbeat against official safety advice.

Protein may protect against heart attack

July 14, 2017
DDK3 could be used as a new therapy to stop the build-up of fatty material inside the arteries

Heart study finds faulty link between biomarkers and clinical outcomes

July 14, 2017
Surrogate endpoints (biomarkers), which are routinely used in clinical research to test new drugs, should not be trusted as the ultimate measure to approve new health interventions in cardiovascular medicine, according to ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.