NEJM: Should Patients with Atrial High-Rate Episodes Without Atrial Fibrillation Receive Anticoagulation?

Behnood Bikdeli, MD, MS, reviewing Kirchhof P et al. N Engl J Med 2023 Aug 25

Atrial high-rate episodes (AHREs) represent a potentially heterogenous group of atrial arrhythmias detected by implantable cardiac devices. Although some clinicians consider them equivalent to atrial fibrillation (AF) and prescribe anticoagulant therapy for patients with AHREs who have stroke risk factors, no robust evidence exists for this practice.

In the multinational, double-blind NOAH-AFNET 6 trial (NCT02618577), investigators randomized approximately 2600 patients aged ≥65 years with AHREs lasting ≥6 minutes, ≥1 risk factor for stroke, and no prior AF on surface electrocardiogram (ECG) to receive oral edoxaban 60 mg or placebo once daily. The primary endpoint, assessed as time-to-first-event, was a composite of stroke, systemic embolism, and cardiovascular death. Although there were no prespecified stopping rules for safety, the trial was halted prematurely due to safety concerns. The edoxaban group had numeric (but not statistically significant) reductions in stroke or systematic embolism compared with the placebo group but had a significant increase in major bleeding events (hazard ratio, 2.1) and a numeric increase in noncardiovascular deaths.