What Older Adults with Atrial Fibrillation Should Know About Taking Oral Blood Thinners
Thursday, January 17, 2013
Summary of This Report
Atrial fibrillation (AF) is a common heart rhythm problem that affects more than 1.5 million Americans over the age of 65. If you have AF, your heart beats irregularly and does not pump blood through your body the way it should. Because of this, blood can pool in certain parts of your heart and form a blood clot. If a blood clot breaks away from your heart and gets stuck in a blood vessel in your brain, it can cause a stroke.
To prevent clots and strokes in people with AF, doctors often prescribe medications known as “blood thinners” or “anticoagulants.” These drugs include aspirin, warfarin (the brand name is Coumadin), and other anticoagulation drugs. These drugs help prevent blood clots from forming and may help prevent existing clots from growing larger.
Because these drugs thin your blood, they can increase your risk of harmful bleeding, including bleeding inside your body (internal bleeding). So physicians need to carefully watch patients who are taking blood thinners and make sure they’re getting the right drugs at the right doses. This can be complicated.
Heart rhythm specialists at the Portland Veterans Affairs Medical Center in Oregon recently reviewed research studies, from 1990 to the present, examining the use of blood thinners in older people with AF. Their report, “Oral Anticoagulation in Elderly Adults with Atrial Fibrillation: Integrating New Options With Old Concepts,” was published in the Journal of the American Geriatrics Society (JAGS).
Nine Things to Know About the Evaluation and Treatment of Atrial Fibrillation in Older Adults
The researchers’ article describes the following nine things that clinicians should consider when deciding how to treat older patients with AF:
- The “CHA2DS2-VASc” formula. This formula is one of the things doctors use to figure out how likely it is that a patient with AF will develop blood clots, whether he or she needs blood-thinning drugs, and if so, which drug.
The name of the formula stands for key risk factors for clots. These risk factors are: having Congestive heart failure, having Hypertension (or high blood pressure), being Age 75 or older (CHA2), having Diabetes, having had a Stroke or “mini-stroke” (transient ischemic attack) (DS2), having Vascular (or blood vessel) disease, being Age 65 to 74, and belonging to the “female Sex Category” (VASc) (Age of 75 and older and stroke or “mini-stroke” raise the risk of blood clots and stroke more than the other risk factors do.)
- Warfarin lowers patients’ risk of AF-related blood clots and strokes more than either aspirin or a combination of aspirin and another blood thinner called clopidogrel. However, warfarin may not be best for certain patients who are at very low risk for stroke and/or at very high risk of bleeding.
- Doctors also use formulas to predict how likely a patient is to have bleeding problems if he or she takes anticoagulation medications. Many factors that boost patients’ risk of stroke also boost their risk of bleeding caused by anticoagulant drugs. This can make treatment decisions based on benefits versus risks difficult.
- Older adults who take warfarin often run a higher risk of bleeding than younger adults taking the medication. In part this is because older people tend to have additional health problems that can increase this risk, and because they often take more medications, some of which can increase this risk. Healthcare providers need to keep this in mind and should be especially careful when combining drugs like aspirin with warfarin since both drugs are blood thinners.
- While older adults run increased risks of falling, and falls can cause bleeding, this doesn’t mean older people shouldn’t use warfarin. Why? Because it’s unusual for older patients taking the drug to have dangerous bleeding, such as bleeding inside the skull, after a fall. It can be more dangerous not to give warfarin to older adults with AF because that would increase their chances of having a stroke.
- Anticoagulant therapy isn’t used as often as it should be. There are several reasons for this, including the need for regularly monitoring the effect of warfarin and dosing the medication, as well as an unwillingness to face small risks of bleeding.
- Three oral anticoagulants have become available as alternatives to warfarin: dabigatran (brand name Pradaxa), rivaroxaban (brand name Xarelto), and apixaban (brand name Eliquis). They don’t require the regular blood monitoring that warfarin does, and have been found to be as good as or better than warfarin in preventing both strokes and bleeding complications in people with AF. But they’re not for everyone.
- Sometimes oral anticoagulants, such as warfarin, need to be reversed quickly because of major bleeding or the need for emergency surgery. This can be difficult, especially with the new oral anticoagulants. This is because, to date, there is nothing that can be given to the patient that quickly reverses the drugs’ blood- thinning effects. Fortunately, their blood-thinning effects aren’t as long-lasting as warfarin’s.
- When a patient taking a blood thinner for AF needs a scheduled surgery or invasive procedure, his or her healthcare providers need to take the proper steps to minimize both bleeding and the formation of blood clots. Sometimes this involves stopping the drug at the right time before the procedure, and then re-starting it at the right time after the procedure.
This summary is from the full report titled, “Oral Anticoagulation in Elderly Adults with Atrial Fibrillation: Integrating New Options with Old Concepts.” It appears in the January 2013 issue of the Journal of the American Geriatrics Society. The report is authored by Ignatius Gerardo E. Zarraga, MD, and Jack Kron, MD.