Among patients who met the primary endpoint in REVEAL AF, 10.2% had one or more AF episodes lasting 24 hours or more. So a significant proportion of the asymptomatic episodes of AF were not brief.
The take-home lesson of this analysis is straightforward, he said. “While the incidence of screen-detected atrial fibrillation is dependent upon the population screened, it is also strongly dependent upon the duration and intensity of monitoring.”
Session cochair Jeanne E. Poole, MD, observed that while the new REVEAL AF analysis is informative, it leaves unanswered the big questions regarding the clinical importance of these silent episodes of subclinical device-detected AF. That is, are these episodes associated with significantly increased stroke risk, and if so are they just another nonmodifiable risk marker, or are they a risk factor that can be dampened via oral anticoagulation, like symptomatic AF? said Dr. Poole, professor of medicine and director of the clinical cardiac electrophysiology program at the University of Washington, Seattle.
“My own belief is that they are both a risk marker and a risk factor that contributes to stroke,” Dr. Reiffel replied.
He noted that there are two major ongoing clinical trials evaluating the impact of oral anticoagulation in patients with ICM-detected AF. The 3,400-patient German multicenter Non–vitamin K Antagonist Oral Anticoagulants in Patients With Atrial High Rate Episodes (NOAH–AFNET 6 ) trial is testing whether oral anticoagulation with edoxaban (Savaysa) is superior to aspirin or no antithrombotic therapy for prevention of stroke or cardiovascular death. And the 4,000-patient Apixaban for the Reduction of Thrombo-Embolism in Patients With Device-Detected Sub-Clinical Atrial Fibrillation (ARTESIA) trial is randomizing patients to apixaban (Eliquis) or aspirin.