Oral anticoagulation not recommended for people with atrial high-rate episodes

medwireNews: Anticoagulation with edoxaban does not reduce the risk for a composite outcome of stroke, systemic embolism, or cardiovascular death, and increases the incidence of bleeding in individuals with device-detected atrial high-rate episodes (AHREs), indicate trial data. “NOAH-AFNET 6 demonstrates that anticoagulation should not be used in patients with AHRE until atrial fibrillation is documented by ECG [electrocardiogram],” investigator Paulus Kirchhof (University Medical Center Hamburg–Eppendorf, Germany) told the press at the ESC Congress 2023 in Amsterdam, the Netherlands. He continued: “Better methods to estimate stroke risk in patients with rare atrial arrhythmias are needed.” Outlining the background to the study, the presenter explained that the cardiac electrical activity recorded during AHREs resembles that recorded during atrial fibrillation and clinicians often initiate oral anticoagulant therapy, but whether such treatment is justified remains unknown. The research team therefore initiated the double-blind, double-dummy NOAH-AFNET 6 trial, which recruited 2536 patients aged 65 years or older with AHREs detected by implanted devices that lasted 6 minutes or longer, at least one risk factor for stroke, and no history of atrial fibrillation as documented on an ECG. Participants were aged an average of 77.5 years and 37.4% were women; the median duration of AHREs was 2.8 hours. At a median follow-up of 21 months, the primary efficacy outcome of a first occurrence of a composite of cardiovascular death, stroke, or systemic embolism occurred in 83 of the 1270 given edoxaban 60 mg twice daily and 101 of the 1266 patients given placebo, giving a comparable incidence per patient–year of 3.2% and 4.0%. By contrast, the safety outcome of a composite of death from any cause or major bleeding occurred significantly more frequently in the edoxaban than placebo group, at 5.9% versus 4.5% per patient–year. Kirchhof also reported on secondary outcomes, noting that the incidence of stroke was low in both the edoxaban and placebo study arms (0.9 vs 1.1% per patient–year), which was “surprising,” and the incidence of major bleeding was over twofold higher in the edoxaban than the placebo group, which was “as expected” with anticoagulation. He added that the trial was terminated early on the recommendation of the data and safety monitoring board and the steering committee. Discussant Elena Arbelo, from the University of Barcelona in Spain, said that the guidelines currently recommend the confirmation of arrhythmias by ECG before initiating anticoagulation, and “this will need to stay this way.” The NOAH-AFNET 6 findings are simultaneously published in The New England Journal of Medicine. medwireNews is an independent medical news service provided by Springer Healthcare Ltd. © 2023 Springer Healthcare Ltd, part of the Springer Nature Group ESC Congress 2023; Amsterdam, the Netherlands: 25–28 August N Engl J Med 2023; doi:10.1056/NEJMoa2303062

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Oral anticoagulation not recommended for people with atrial high-rate episodes

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