For decades, the vitamin K agonist warfarin provided the only option for stroke prevention in patients with atrial fibrillation (AF), but since 2010, the U.S. Food and Drug Administration has approved four direct oral anticoagulants (DOACs)—dabigatran, rivoroxaban, apixaban and edoxaban—for this indication. While the European Society of Cardiology recommends the DOACs over vitamin K agonists for stroke prevention in AF patients, the American College of Cardiology gives both types of anticoagulants equal status in its guidelines. Which type do U.S. cardiologists prefer?

A study presented this weekend at the American Heart Association Scientific Sessions 2018 found that preference varies with the number of risk factors for stroke a patient has. At CHAD2DS2-VASC scores of 0 to 2, community cardiologists prescribed DOACs with greater frequency. At scores of 2 to 3, the two types of anticoagulants had about equally as likely to be prescribed. As scores rose from 3 to 8, however, a strong preference for warfarin emerged. At 6, about one-third of prescriptions were for DOACs but at 8, almost none were.

AHA meeting. Photo courtesy of AHA

The researchers did not find that the preference was driven by increased risk of ischemic stroke, gastrointestinal bleed or intracranial hemorrhage in DOACs versus warfarin. In fact, they determined that patients were 40% less likely to experience intracranial hemorrhage with DOACs. DOACs were also associated with lower rates of stroke and GI bleed, though the results were determined to be non-significant in multivariable analysis.

For the study, the research team analyzed the results of 2,362 patients with newly diagnosed atrial fibrillation admitted to the University of Arkansas between 2014 and 2017. Warfarin was prescribed to 1,306 patients, while 1,056 received a DOAC. At the beginning of the study, only dabigatran and rivoroxaban had received FDA approval.

Based on the results seen in the study, the investigators recommended “larger studies assessing safety of DOACs in patients with high CHAD2DS2-VASC” scores.

Mo1296 / 1296 - Prescription Patterns and Outcomes of Direct Oral Anticoagulants and Warfarin in Patients With Atrial Fibrillation a Real World Analysis