If you’ve been diagnosed with atrial fibrillation (AFib) -- a heart rhythm disorder in which the two upper chambers, known as the atria, quiver instead of beating at a steady pace -- your doctor will have two main goals for treatment.
You may be surprised to learn that resetting your heart’s rhythm is the second goal of AFib treatment. People with atrial fibrillation are five times more likely to have a stroke than those who don’t have AFib, so your doctor’s first concern will be lowering your stroke risk. “The biggest health risk from the AFib itself is that clots will form in the heart and cause a stroke,” says William Whang, MD, assistant professor of clinical medicine in the division of cardiology at Columbia University Medical Center.
Once the stroke risk is under control, you can treat the actual atrial fibrillation rhythm disorder.
Doctors assess the risk of stroke in people with atrial fibrillation using a formula called CHADS2. It stands for:
- C-Congestive heart failure
- H-High blood pressure
- A-Age 75 or older
- S2-Previous stroke
Each of the conditions earns you one point; a previous stroke gets you two. Recently, doctors have added a second half to the scoring system, which evidence shows is even more accurate. This formula, known as VASc, adds points for being a woman (women with AFib are at greater stroke risk), peripheral vascular disease, and being older than 65.
“The general recommendation is that all but the lowest-risk AFib patients take a blood thinner, such as Coumadin,” says John Wylie, MD, director of electrophysiology services for Massachusetts-based Caritas Christi Health Care. “Patients who score only a point on CHADS2-VASc should be fine taking daily aspirin to manage their stroke risk, but if your score is higher than one point, I will recommend Coumadin. I’ve seen too many strokes.”
Blood thinners come with their own risks, such as gastrointestinal bleeding, joint problems, and uncontrolled hemorrhage. If your doctor puts you on a blood thinner, you also should be carefully monitored with regular blood tests.
In 2010, the FDA approved a new drug, dabigatran (Pradaxa), specifically to prevent stroke in people with AFib not caused by a heart valve problem. Although this drug also carries with it a risk of bleeding, it doesn’t require the same monthly blood tests that Coumadin does.
“It’s more convenient and it may be slightly more effective,” Wylie says. “On the other hand, it’s also more expensive and not all insurance plans may cover it, and it’s more difficult to reverse quickly if someone is in a traumatic accident that causes bleeding.”
Rivaroxaban (Xarelto) is an even newer drug in a similar category. It does not need to be monitored with monthly blood tests and is prescribed only once a day. Eliquis is also a blood thinner that does not require monthly blood tests. It's taken twice a day.