Nearly all people older than 65 in the United States (US) with atrial fibrillation (AF) are advised to take blood thinners under new guidelines based on an analysis from the Duke Clinical Research Institute (DCRI).
AF is an irregular heartbeat that can lead to blood clots, stroke, heart failure, and other heart-related complications. It affects about 2.7 million people in the US. In 2014, the American Heart Association, American College of Cardiology, and Heart Rhythm Society issued broader guidelines for the use of anticoagulants in treating AF.
Notably, being female is now included in the guidelines as a contributing risk factor for stroke, says Emily O’Brien, PhD, lead author of the Duke study, published in JAMA Internal Medicine.
Analysts at DCRI reviewed data from a registry called ORBIT that included 10,132 AF patients from 176 sites across the US. They examined patients’ age, gender, and other risk factors such as prior congestive heart failure, high blood pressure, diabetes, and prior stroke. The analysis provides a roadmap for how the broader guidelines could affect the number of patients recommended for drug therapy.
The researchers reported that the overall proportion of AF patients recommended for blood-thinning drugs would increase by 19% as a result of the new guidelines, from about 72% to 91% of all AF patients.
A similar increase was predicted for women with the heart condition. Under previous guidelines, about 77% of female AF patients in the study population would have been recommended for treatment with anticoagulants; under the new guidelines, this increases to 98%.
The new recommendations also lower the age at which patients are considered to have a risk of stroke (from age 75 to age 65). In the study population, this meant that almost 99% of patients with AF older than 65 could now be recommended for blood thinners, versus roughly 80% whose stroke risk was severe enough under the previous criteria to suggest drug therapy.
“The full adoption of the guidelines could reclassify nearly 1 million people with AF who previously weren’t recommended for treatment with blood thinners,” O’Brien says. “What we don’t know yet is the extent to which doctors in community practice will incorporate the guidelines into their clinical routines and what that will mean for the long-term outcomes for those patients. That will be the next step for our study.”
Although the new guidelines are evidence based, they are just one factor that a physician should consider when planning treatment regimens, O’Brien says. Doctors should also weigh the possible risks and benefits of drug treatment, as well as the patient’s goals and values, she says.