More than one-in-three atrial fibrillation (AFib) patients with an intermediate-to-high-risk of stroke are prescribed aspirin instead of oral anticoagulants, despite guidelines recommending the use of anticoagulants for this population, according to a study published June 20 in the Journal of the American College of Cardiology.

Using data from ACC's PINNACLE Registry, researchers looked at records from 210,380 patients with a CHADS₂ score greater than or equal to two between January 2008 and December 2012. In a secondary analysis, the researchers assessed records from 294,642 patients with a comparable CHA₂DS₂-VASc score during the same timeframe.

Results showed that among the CHADS₂ group, 38 percent were treated with aspirin, and nearly 62 percent were treated with oral anticoagulants. Among the CHA₂DS₂-VASc group, 40 percent were treated with aspirin, while 60 percent were treated with oral anticoagulants.

For both groups, AFib patients who were prescribed aspirin were younger, had a lower body mass index, were more likely to be female, and were more likely to have another medical condition, including diabetes, hypertension, high cholesterol, or coronary artery disease. Those prescribed oral anticoagulants were more likely to be male, have a higher body mass index, a history of a prior stroke or blood clot, or a history of congestive heart failure.

Jonathan C. Hsu, MD, MAS, FACC, the study’s lead author, says cardiovascular specialists may be prescribing aspirin instead of oral anticoagulants because they have "the misperception that aspirin exhibits adequate efficacy compared to oral anticoagulants." He also notes that men had a 6 percent greater likelihood of being prescribed anticoagulants despite the fact that women have an increased risk of stroke.

In an accompanying editorial, Sanjay Deshpande, MD, and L. Samuel Wann, MD, explain that "it is concerning that the highly motivated, conscientious, and talented cardiologists working in quality-conscious institutions that contribute their data to the NCDR are not prescribing anti-coagulation in one-third of their qualifying patients, as defined by our guidelines."

They acknowledge that anticoagulation is difficult, "entailing compliance with a long-term regimen that many patients and their physicians find burdensome." Nonetheless, "new and definitive evidence" demonstrates that anticoagulation, not aspirin, is the treatment of choice to prevent strokes related to AFib, they add.

Keywords: Anticoagulants, Aspirin, Atrial Fibrillation, Body Mass Index, Cholesterol, Coronary Artery Disease, Diabetes Mellitus, Heart Failure, Hypertension, Registries, Research Personnel, Risk, Specialization, Stroke, Thrombosis, PINNACLE Registry, National Cardiovascular Data Registries

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