Atrial fibrillation is the most common form of heart arrhythmia. The main goal of treatment for atrial fibrillation 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.
‘Atrial fibrillation (Afib) patients are even more likely to discontinue warfarin therapy if they've had a recent procedure done to address their arrhythmia.’
A new research letter published in JAMA Cardiology
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, 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
The researchers found 36.8% 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, 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%) 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%)
Although the numbers are much higher for those who underwent a
procedure, 29.5% 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