There are few feelings as unsettling as the out-of-whack heartbeat of atrial fibrillation (AFib). And while treatment can put your heart back into a normal rhythm, that’s not quite the good news it may seem.  New research shows that even for people told they no longer had AFib, the increased stroke risk—the biggest threat of the condition—may remain.

Background: AFib occurs when the upper chambers of the heart, the atria, beat irregularly—more like a quiver than a normal beat—and don’t effectively move blood into the lower chambers of the heart, the ventricles. This can lead to blood clots that can travel to the brain, causing a stroke. Between 15% and 20% of all strokes are in people with AFib. Looked at another way, in people with AFib, the risk of stroke is five times higher, on average, than in similar people without it. Treatment for AFib usually includes a blood-thinning drug to prevent clots—this can reduce stroke risk by 66%.

Sometimes in AFib patients, the heart appears to resume beating regularly, either on its own or after an ablation, a procedure to correct the irregular rhythm. If the results of an EKG are normal, your doctor may tell you that your AFib has “resolved” or gone away. But there’s growing evidence that in these cases, AFib might not really be gone…and that patients shouldn’t stop taking life-saving blood thinners.

New study: Researchers from University of Birmingham in the UK looked into the medical records of nearly 50,000 people in that country and compared the number of stroke cases among those with active AFib…those with so-called resolved AFib…and those with no history of AFib.

Troubling results: Patients with resolved AFib were still 63% more likely to have a stroke or a transient ischemic attack (TIA, or “mini-stroke”) than people who had never had AFib. That’s just 25% lower risk than people with active AFib.

In other words, these people who had been declared AFib-free were still in grave danger in way similar to when they had AFib.


Tom Marshall, MB ChB, PhD, the study’s lead author, explains that there are a number of reasons why AFib can be simmering below the surface despite no obvious signs. Some people may have intermittent AFib—and the heartbeat might not be irregular at the moment of medical testing. Even after a successful ablation, up to one half of patients develop AFib again within the next year, and each passing year raises the likelihood by a few more percentage points. These possibilities support the study’s suggestion that more people should keep taking blood thinners to reduce their stroke risk.

Continued blood thinner treatment often is determined by how patients score on stroke-risk assessment tests, such as ATRIA. These tests assign points for individual risk factors such as diabetes, high blood pressure and older age. Another assessment, called HAS-BLED, developed at te University of Birmingham, does the best job of predicting bleeding risk, the most dangerous side effect of taking blood thinners, according to a review published in Clinical Cardiology. The Birmingham findings underscore the importance of getting one or more of these assessments and carefully reviewing the results with your doctor to help determine the best way to protect your heart and avoid stroke—because even if your AFib is considered resolved, a high score is a strong indicator that staying on a blood thinner is right for you.

To decrease your risk for stroke from AFib, Dr. Marshall also has these reminders…

  • Stop smoking
  • Stay physically active
  • Maintain a healthy weight
  • Control your blood pressure

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