Atrial Fibrillation (AFib) and Stroke Risk
Atrial fibrillation causes the atria to beat so fast and irregularly that there is no meaningful contraction or motion in the upper chamber of the heart. There are areas in the upper chamber where blood can stay relatively stagnant when in AFib – The left atrial appendage is the most important one. This makes the blood more likely to clot.
If a clot develops in the appendage and is pumped out of the heart, it can travel to the brain, where it will cut off circulation, resulting in a stroke. People with atrial fibrillation are 5 to 7 times more likely to have a stroke than the general population. It is estimated that over 90% of strokes happening in patients with AFib come from blood clots formed in the left atrial appendage. Clots can also travel to other parts of the body (kidneys, heart, intestines), and cause other damage.
Studies have shown that the risk of stroke increases when patients have other risk factors. We typically use the CHADS2 or CHADS2-Vasc risk scoring systems to predict one’s annual risk of stroke.
The more risk factors for stroke a patient has, the higher the annual risk of stroke. That is, your risk of having a stroke each year will increase significantly the more points you have.
The appropriate treatment to decrease your risk of stroke will depend on how high the risk is of you having a stroke compared to the risk of bleeding from taking a blood thinner. If your CHA2D2-VASc score is two or greater, you should be on some form of blood thinner. The physician also needs to weigh the risk of bleeding, based on the HASBLED score, while you are taking a blood thinner. Discuss with your physician the best treatment option for you.
Options to Reduce the Risk of Strokes
- Blood thinner medications: the most commonly used treatment to reduce strokes.
- Warfarin (Coumadin)
- Newer drugs like Eliquis, Pradaxa, Savaysa, or Xarelto
- Left atrial appendage closure (LAAC): 90% of strokes in patients with AFib are caused by clots coming from the appendage. In some patients, appendage occlusion is an alternative option to reduce the risk of stroke.
The Watchman device is an alternative to long-term oral anticoagulation (blood thinner) in some patients. Although blood thinner medicines work well at preventing stroke, not all patients with AFib are able to take them.
Dr Jose Osorio
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