There are millions of patients throughout the United States living with atrial fibrillation. Atrial fibrillation is the most common irregular heart rhythm, which can significantly increase a patient’s risk of stroke. A patient with atrial fibrillation is 5 times more likely to have a stroke then someone without atrial fibrillation. But why is someone with atrial fibrillation more likely to have a stroke?
In atrial fibrillation, the upper chambers of the heart, also called the atria, are beating so fast that they are quivering, and as a result the blood is not flowing properly. This can then lead to stagnant blow blood flow, which could then result in a blood clot.
Over 90% of blood clots formed due to atrial fibrillation occur in the left atrial appendage. The left atrial appendage is a small pouch in a person’s left atrium, or left upper chamber of the heart. This is where the main risk of stroke comes from in patients with atrial fibrillation; a blood clot typically forms in the left atrial appendage and then can travel in a patient’s bloodstream to the brain and give a patient a stroke. See image below for an ultrasound picture with an example of a large blood clot in a patient’s left atrial appendage.
For decades, the main way to reduce risk of stroke in patients with atrial fibrillation was with blood thinning medications. There are many blood thinning medications currently available. By thinning a patient’s blood, these medications can significantly reduce a patient’s risk of stroke, typically by 65-75%. Although these medications can be very effective for reducing risk of stroke, all these medications carry risks for major bleeding.
Because of this risk for major bleeding, there are many patients who are unable to tolerate standard recommended blood thinners. Patient’s on blood thinners may have recurrent hospitalizations for significant bleeding, or may develop significant anemia due to slow chronic blood loss.
In patients with atrial fibrillation who have experienced difficulties with blood thinners including significant bleeding, a Watchman device may be an excellent option. A Watchman is a small device that covers or occludes the left atrial appendage, where the main risk of stroke occurs.
The Watchman device is delivered through a catheter, which then is guided to your heart through a large vein in your leg, similar to a heart catheterization procedure. It is typically done under anesthesia; the procedure typically takes less than an hour to do. Patients typically stay in the hospital one night and are able to be discharged to home the following day. After receiving a Watchman device, patient still need to remain on blood thinners for about 6 weeks, this is to allow the Watchman device to be completely sealed off with a patient’s own heart tissue that grows over the device.
Over 90% of watchman patients are able to come off blood thinners 6 weeks post procedure. Coming off blood thinners can significantly improve a patient’s risk for major bleeding and anemia.
In the Watchman trials, the risk of stroke after receiving a Watchman device is overall similar, or non-inferior in clinical trial terms, when it was compared to warfarin for stroke risk reduction. The risk of stroke does not become zero, but it is equivalent to being on a blood thinner but without the major bleeding risks. It does, however, significantly improve a patient’s risk of stroke compared to not taking any blood thinners at all.
The Watchman device has been FDA approved since 2015, and has been implanted in over 50,000 patients worldwide. It represents an excellent option for stroke risk reduction in patients with atrial fibrillation, especially in patients who are unable to tolerate standard recommended blood thinners. There are many patients who have legitimate reasons they cannot tolerate standard recommended blood thinners, in these settings a Watchman can be excellent option for reducing risk of stroke. As always, please discuss with your personal doctor to see if you are a candidate for a Watchman procedure and too see if it is the right procedure for you.