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Atrial Fibrillation Q & A with Ramanna Merla, MD

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Atrial Fibrillation Q & A with Ramanna Merla, MD


Electrophysiologist at Pomona Valley Hospital Medical Center

Q: How great is the risk of stroke for people with atrial fibrillation (AFib)?

A: The risk of stroke depends upon something called the Chadsvasc Score, which calculates stroke risk in AFib patients by scoring the contributing risk factors. These include:

Congestive heart failure


Age (the risk is higher for patients 65 years old and older)


Stroke (whether the patient has had a stroke previously)

Vascular disease and gender (the risk is higher in women).

Doctors may prescribe anticoagulant drugs (blood thinners) if a patient scores a two or higher. About 80 percent of strokes caused by AFib can be prevented by anticoagulant therapy.

Q: How great is the risk of developing a blood clot that might cause a stroke?

A: It’s quite high in AFib patients; it can be as high as 30 percent. Ninety percent of these clots form in the left atrial appendage.

Q: Who should consider closure of the left atrial appendage?

A: Those who cannot tolerate long-term blood thinners. This might include someone who has a GI bleed; someone at risk of injury from frequent falls; anyone who has previously had a bleed in the brain; and people with active lifestyles such as bicyclists or marathon runners. Since blood thinners slow the clotting of blood, dangerous bleeding can occur with some injuries.

It also depends on the patient’s preference. Left atrial appendage closure is simply an alternative to blood thinners. Some patients prefer to remain on anticoagulation therapy.

Q: Who is not a good candidate for left atrial appendage closure?

A: Somebody who is already taking blood thinners for other reasons, such as blood clots in the legs. Since they will need to continue taking blood thinners, there’s no advantage to closing the left atrial appendage. They’re also not a good candidate if their risk of blood clot is very low – for example, a 40-year-old male with none of the risk factors as measured by the Chadsvasc score. The Chadsvasc score must be greater than three before we will consider closure.

Q: What are the risks associated with left atrial appendage closure?

A: There is a less than 1 percent chance of fluid buildup around the heart, which would need to be drained. There’s an equally small risk of leak next to the device, which would require you to continue taking blood thinners, and a slight risk of the device dislodging or of having a stroke during the placement procedure. All the risks together total about 1.6 percent.

Q: What’s the biggest benefit of left atrial appendage closure?

A: That you can stop taking blood thinners. About six months after closure, if there are no complications, you simply need to take an aspirin for the rest of your life. So, someone who’s 65 years old and lives to be 95 has 30 years without having to take blood thinners; no risk of bleeding in the brain and no risk of bleeding after a fall. They also don’t have to remember to take their medication; if you’re on blood thinners, each time you forget to take your medication you increase your risk of stroke.