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Atrial Fibrillation
Heart Health

Some Afib Patients Get Unnecessary Blood Thinners

About a quarter of all atrial fibrillation (AF) patients at the lowest risk for stroke receive unnecessary blood thinners from cardiology specialists, according to researchers at the University of California, San Francisco who contend that the providers must be made aware of the resulting potential health risks.

Their research letter appears online and will be in the June 1st  issue of JAMA Internal Medicine.

A release from the university quotes senior author Gregory Marcus, MD, MAS, director of clinical research in the UCSF Division of Cardiology, as saying, “The irony is that there is a general push to get providers to prescribe these drugs, and they are also generally under-prescribed among many AF patients who actually need them. Our study suggests people are trying to do the right thing but, due to a lack of understanding of some of the critical nuances, go too far in that direction in low-risk patients.”

In AF, electrical impulses are triggered from many areas in and around the upper chambers (atria) of the heart instead of just one area. This activity is chaotic, and the atrial walls quiver rather than contract normally in moving blood to the lower chambers (ventricles).

For atrial fibrillation patients at risk for thromboembolism, anticoagulation therapies with warfarin or other drugs reduce morbidity and mortality. But because their use carries a bleeding risk, they are not recommended for AF patients at a particularly low risk for stroke.

In fact, current guidelines do not recommend oral anticoagulation in patients under age 60 without heart disease or other known risk factors for thromboembolism or in AF patients without any established risk factor for stroke. The previous guidelines, which were in place at the time the data for this study were collected, had, in fact, a very strong recommendation specifically to avoid anticoagulants in that population.

Marcus and his colleagues examined the prevalence of non-guideline adhering oral anticoagulant prescription in young and healthy patients at the lowest risk for thromboembolism by reviewing nearly 11,000 patients nationwide age 60 and under from the overall Practice Innovation and Clinical Excellence (PINNACLE) Registry® of the National Cardiovascular Data Registry between 2008-2012. The PINNACLE Registry was created in 2008 by the American College of Cardiology as the first national, prospective, office-based cardiac quality improvement registry in the United States and enrolled more than 1.7 million patients.

Surprisingly, about 25 percent of patients (2,561) were prescribed oral anticoagulant therapy contrary to contemporary guideline recommendations. Further, the researchers found males with AF at the lowest risk of stroke were more likely to be prescribed oral anticoagulation than females, as were older patients and overweight patients without stroke risk factors.