CLINICAL QUESTION: Does apixaban reduce the risk of stroke or systemic embolism compared to aspirin in patients with subclinical atrial fibrillation and elevated stroke risk?
BACKGROUND: Subclinical AF, often detected via implantable cardiac devices, is associated with an increased risk of stroke based on observational data. Previously, NOAH-AFNET6, a trial of 2,536 patients, did not show reduced risk of stroke but did note a 31% increase in major bleeding when comparing edoxaban versus placebo in patients with subclinical AF. Thus, ARTESIA was designed as a larger trial with longer follow-up, meant to answer this question.
STUDY DESIGN: Multicenter, double-blind, randomized controlled trial
SETTING: 263 sites across Europe and North America
SYNOPSIS: In this study, 4,102 patients aged 55 years and older with subclinical AF lasting six minutes to 24 hours and with a CHA₂DS₂-VASc score of 3 or higher were randomized to receive either aspirin 81 mg daily or apixaban 5 mg twice daily. Most patients had AF detected for less than six hours. After a mean follow-up of 3.5 years, the rate of stroke or systemic emboli was higher in the aspirin group versus the apixaban group (1.24% versus 0.78% per patient-year, P = 0.007). However, patients in the apixaban group had more major bleeding events than their controls in the aspirin group (1.53% versus 1.12% per patient year, P = 0.04).
BOTTOM LINE: In patients with subclinical AF and elevated stroke risk, apixaban reduced the incidence of stroke or systemic embolism compared to aspirin but was associated with a higher risk of major bleeding.
CITATION: Healey JS, et al. Apixaban for stroke prevention in subclinical atrial fibrillation. N Engl J Med. 2024;390(2):107-117. doi:10.1056/NEJ-Moa2310234
Dr. Giordano
Dr. Giordano is a hospitalist at Duke Regional Hospital and a medical instructor at the Duke University School of Medicine, both in Durham, N.C.