If you have atrial fibrillation, you have an increased risk of stroke. The stroke in atrial fibrillation varies from patient to patient depending on their profile and other conditions that they have. On Average the stroke risk increases by about 5 folds in atrial fibrillation compared to patients without atrial fibrillation. The risk of stroke in atrial fibrillation is reduced, on average by about 50% to 60% by taking a blood thinner (Anticoagulant).
Stroke occurs when blood flow to the brain is stopped by a clot, preventing brain cells from obtaining the necessary oxygen. In people with atrial fibrillation, blood flow is sluggish in the top chambers of the heart because they are effectively “quivering” and not contracting to move the blood through the circulation. This stagnation of blood can cause a blood clot to form in the heart. When a piece of a blood clot breaks off, it can travel to the brain and cause a stroke. That is where blood thinners can help. Blood thinners, or anticoagulants, decrease the chances of blood clots forming in the heart and hence reducing the risk of stroke.
But as many as half of the people with atrial fibrillation who could benefit from a blood thinner don’t take them, mostly because of improper evaluation and treatment of their atrial fibrillation.