If your doctor has prescribed anticoagulants (blood thinners) to you because you have atrial fibrillation (AFib), he or she may be putting you in harm’s way, finds a new study.

Let’s say you don’t have heart disease, diabetes or high blood pressure. You’ve never had a blood clot or a stroke. But you do have AFib, an irregular heartbeat condition that affects about 5 million Americans and increases the risk for stroke by an average of 400% or more compared to people without AFib.

So your doctor prescribes an anticoagulant (blood-thinning) medication that has been shown to reduce the risk for stroke in patients with AFib. Is that a good idea?

Actually, it’s not—at all.


Cardiology evidence-based guidelines advise against anticoagulant medications for healthy younger patients—even those with AFib. Why? Anticoagulants increase the risk for dangerous gastrointestinal or cerebral bleeding—even a slip of the dental floss can lead to serious bleeding—so these drugs should be used only when their benefits clearly outweigh their risks. For people with AFib who are nonetheless at low risk for stroke, anticoagulant drugs are just not worth taking.

Now a new study finds that many doctors prescribe them for just these kinds of patients. Researchers examined the records of 11,000 AFib patients in 76 cardiology practices across 33 states. These are the AFib patients who were at the very lowest risk for stroke—under age 60, with no other kinds of heart problems (such as valve disease), diabetes or high blood pressure. None were known to have ever had a stroke, a transient ischemic attack (mini stroke) or even a blood clot. According to the guidelines, none of these patients should have been prescribed anticoagulants.

Here’s why: They are at no greater increased risk for stroke than the normal population without AFib.

Yet about 25% of them in this study were prescribed anticoagulants.

To be sure, medicine should be individualized. There are likely some cases where it makes sense for a doctor to prescribe a medication against guidelines, based on a patient’s specific case. But when the numbers are so large, it clearly suggests that many patients are getting medications unnecessarily—and risk being harmed.


Here’s how to protect yourself…

• If you have AFib (or know someone who does) and the doctor prescribes an anticoagulant, ask if it’s absolutely necessary and if so, why. These medications include warfarin (Coumadin), dabigatran (Pradaxa), rivaroxaban (Xarelto), apixaban (Eliquis), and edoxaban (Savaysa). (Aspirin isn’t effective at preventing strokes in people with AFib.) If you are truly at significantly increased risk for stroke, taking these medications may indeed be appropriate, even lifesaving.

• Even if you are 60 or over, yet are free of other stroke risks, it’s still quite possible that the risk of taking anticoagulant drugs outweighs the benefit for stroke prevention. (The guidelines say that, too—the reason the researchers chose people under 60 was so that they could study only those at the very lowest risk.)

• If you and your doctor decide that you’re not a candidate for anticoagulants now, you’ll want to be monitored on a regular basis in case your condition or health risks change. In people with AFib, anticoagulants reduce the risk for the most common form of stroke by about two-thirds. (If you are currently taking an anticoagulants for AFib, be sure you talk to your doctor before you make any changes.)

• Even if you have AFib, you can reduce your risk of moving into the high-stroke-risk category by doing what you can now to prevent high blood pressure, diabetes and other stroke risk factors—keep yourself at a healthy weight, limit your salt and alcohol consumption, don’t smoke, and remain physically active.

Yoga may also help reduce AFib events and improve heart health.

To learn more about identifying who really needs blood thinners, see the Bottom Line article, Blood Thinners for Atrial Fibrillation Patients? A New Tool Shows Who Benefits…and Who Doesn’t.