Atrial fibrillation is an abnormal heart rhythm that can disrupt the normal flow of blood in the heart.
When blood does not flow smoothly, there is a chance that the blood can form clots. If a blood clot has formed in the heart, it can be carried by the bloodstream to other areas of the body (thromboembolism). This is dangerous because the clot can become wedged in a smaller blood vessel and decrease the flow of blood to the area that blood vessel supplies.
A blood clot that travels to the small blood vessels in the brain can decrease or block blood flow to the brain, causing injury to the brain (ischemic stroke).
The chance of forming blood clots is different from person to person. Atrial fibrillation is not the only factor that creates blood clots; some people may have other medical problems that can increase the chance of forming blood clots or having a stroke. Your doctor will consider your situation to decide whether you have a low or high risk of blood clots or stroke.
For a person with atrial fibrillation who has a significant risk of blood clots or stroke, the doctor may recommend an anticoagulation (blood-thinning) medication. Examples of these medications are warfarin or new oral anticoagulants such as dabigatran, rivaroxaban, and apixaban. All of these medications work in the bloodstream to prevent clot formation.
For a person with atrial fibrillation and other medical conditions, such as kidney problems or heart problems like coronary artery disease, the medication plan should be tailored to his or her specific needs. This might mean taking clopidogrel in combination with anticoagulation medication such as warfarin for those with recent heart problems. Certain medications might not be appropriate for people with kidney problems. These decisions are made by carefully considering the details of each patient.
For someone with atrial fibrillation who is at low risk of stroke, the doctor will make a recommendation that fits best for that person. The treatment could still include anticoagulation; however, it might be best for that person not to take any blood thinners or to take aspirin alone.
Blood-thinning medications have risks, most importantly the risk of bleeding. Because these medications prevent clotting, any bleeding that is caused by a fall or cut will not stop normally. Other problems with bleeding can occur, such as bleeding into the gastrointestinal tract or bleeding inside the head (hemorrhagic stroke). It is important to consider the risks of bleeding before starting a blood-thinning medication. Bleeding risks do not mean that a person cannot take an anticoagulation medication, only that the person will need to be careful to minimize the risk of bleeding complications.
Atrial fibrillation can increase the risk of thromboembolism and ischemic stroke. Treatment for atrial fibrillation might require anticoagulation, but each patient should be considered individually. The risk of stroke needs to be considered with other medical details, such as the risk of bleeding, to determine the best plan for each patient.
American Heart Associationwww.heart.org
American College of Cardiologywww.acc.org
Heart Rhythm Societywww.hrsonline.org
National Institutes of Healthwww.nhlbi.nih.gov
To find this and previous JAMA Patient Pages, go to the Patient Page link on JAMA’s website at jama.com. Many are available in English and Spanish.
Sources: Lip GYH, Lane DA. Stroke prevention in atrial fibrillation: a systematic review. JAMA. 2015;313(19):1950-1962.
January CT, Wann L, Alpert JS, et al. 2014 AHA/ACC/HRS guideline for the management of patients with atrial fibrillation: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines and the Heart Rhythm Society. J Am Coll Cardiol. 2014;64(21):e1-e76.
Conflict of Interest Disclosures: The authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest and none were reported.
Topic: Vascular Disease
Berian JR, Livingston EH. Preventing Stroke in People With Atrial Fibrillation. JAMA. 2015;314(3):310. doi:10.1001/jama.2015.6779