Oral anticoagulants underused for stroke prevention in patients with nonvalvular AF

SAN DIEGO — New data from the GLORIA-AF registry suggest that patients with nonvalvular atrial fibrillation at high risk for stroke are undertreated with oral anticoagulants and initial therapy in this population is not often prescribed in accordance with guideline recommendations.

Researchers presented two analyses from the second phase of the GLORIA-AF registry program, which was created to characterize patients newly diagnosed with nonvalvular AF at risk for stroke and to study different treatment regimens. The program was started after dabigatran (Pradaxa, Boehringer Ingelheim) became available.

Use by AF pattern

In one analysis, Jonathan L. Halperin, MD, the Robert and Harriet Heilbrunn professor of medicine at the Icahn School of Medicine at Mount Sinai, and colleagues assessed treatment in relation to CHA₂DS₂-VASc score and pattern of AF in 3,415 patients in North America who were enrolled between November 2011 and February 2014. The median age was 71 years, 44.8% were women, 86% had a CHA₂DS₂-VASc score of at least 2, 80% had with hypertension and 27% had diabetes.

Jonathan L. Halperin

In the population studied, 65.9% had paroxysmal AF, 29.5% had persistent AF and 4.6% had permanent AF.

Among patients with a CHA₂DS₂-VASc score of at least 2, 21.9% with paroxysmal AF were not given a vitamin K antagonist or a novel oral anticoagulant vs. 12.4% of those with persistent AF and 11.2% with permanent AF, Halperin and colleagues reported. According to the study background, guidelines recommend anticoagulation with vitamin K antagonists such as warfarin or novel oral anticoagulants for patients with nonvalvular AF and additional stroke risk factors, regardless of the pattern of AF.

“Initial antithrombotic therapy diverged from guideline recommendations,” the researchers wrote in the study abstract.

Use by age

In the same population, Halperin and colleagues also assessed treatment patterns by age and CHA₂DS₂-VASc score.

Overall, they found that 26.1% of patients were treated with a vitamin K antagonist, 25% with dabigatran, 20.5% with rivaroxaban (Xarelto, Janssen Pharmaceuticals), 13.5% with aspirin, 7.6% with no antithrombotic therapy and 6.6% with apixaban (Eliquis, Bristol-Myers Squibb/Pfizer).

Among patients with a CHA₂DS₂-VASc score of at least 2, aspirin alone or no antithrombotic therapy was reported in 20.6% of those aged 64 years or younger, 19.7% aged 65 to 74 years, 15.6% aged 75 to 79 years and 17.6% of those aged at least 80 years, according to the researchers.

In addition, for patients with a CHA₂DS₂-VASc score of at least 2, vitamin K antagonists were the most commonly prescribed therapy, and were used in 27.9% of those aged 64 years or younger, 24.7% aged 65 to 74 years, 27.9% aged 75 to 79 years and 31.7% aged at least 80 years.

Treatment gaps, decisions

“These real-world analyses highlight that while physicians have a variety of factors to consider when deciding on antithrombotic treatment options for [patients with nonvalvular AF], the fact remains that oral anticoagulants, the standard of care for significantly reducing the risk of stroke and systemic embolism in these patients, are underutilized,” Halperin said in a press release. “We need to uncover why that is and what we can do to bridge that treatment gap.” – by Erik Swain

Reference:

Halperin JL, et al. Abstracts 1246-122 and 1246-124. Presented at: American College of Cardiology Scientific Sessions; March 14-16, 2015; San Diego.

Disclosure: The registry is funded by Boehringer Ingelheim. Halperin reports receiving consultant fees/honoraria from AstraZeneca, Bayer, Biotronik, Boehringer Ingelheim, Boston Scientific, Daiichi Sankyo, Johnson & Johnson, Medtronic and Pfizer.