April 4, 2016 – The popularity of the newer drugs may reflect physicians’ growing familiarity with NOACs.
A registry-based study of 4,360 patients with new-onset atrial fibrillation, a common type of heart arrhythmia, found that non-vitamin K antagonist blood thinners for stroke prevention were prescribed more frequently than the long-established alternative, warfarin, including in lower-risk patients.
The newer medications, known as novel oral anticoagulants or NOACs, include apixaban, dabigatran, edoxaban, and rivaroxaban. The NOACs offer several potential advantages over warfarin, including no need for dietary restrictions or blood monitoring, and few drug-drug interactions.
The lead authors, Benjamin A. Steinberg, MD, MHS, (pictured) Jonathan Piccini, MD and colleagues conducted their analysis using the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation (ORBIT-AF II). The results were presented on Monday at the annual Scientific Sessions of the American College of Cardiology in Chicago.
The study population was enrolled across a variety of outpatient settings, including primary care (12 percent), cardiology (72 percent), and electrophysiology (16 percent) practices between 2013-15. Among more than 4,360 patients, 25 percent were started on warfarin, while 75 percent were started on NOACs, including 41 percent on rivaroxaban, 28 percent on apixaban and 6 percent on dabigatran. Drug-selection varied significantly with physician specialty, with NOAC prescription rates of 79 percent among cardiologists, 82 percent among electrophysiologists, and only 44 percent among internists.
“The finding that specialists were more likely to prescribe the NOACs may reflect their greater familiarity with these newer medications,” said Piccini, the senior author of the study. “Our study highlights the importance of looking at variations in prescribing patterns for new medications across specialties. We were surprised to find that patients with more comorbid illness, who might benefit most, were in fact less likely than lower-risk patients to receive these medications.
“Since the NOACs seem to be safer than warfarin, with lower risks of intracranial bleeding, it will be important to determine which patients should receive the older drug,” said lead author Steinberg. “There is a particular need to educate providers on how to select medication for atrial fibrillation, as well as on appropriate care for newly diagnosed patients.”
In addition to Piccini and Steinberg, DCRI authors included Peter Shrader, MA; Laine Thomas, PhD, MD; Emily C. O’Brien, PhD; and Eric D. Peterson, MD, MPH, on behalf of the ORBIT-AF II investigators and patients.