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15-11-2023 | Therapy of Atrial Fibrillation | News

Apixaban superior to aspirin for reducing stroke risk in subclinical AF

Author: Sarah Pritchard


medwireNews: The risk for a disabling or fatal stroke among individuals with subclinical atrial fibrillation (AF) is lower after taking the direct-acting oral anticoagulant apixaban than after aspirin, show the results of an international randomized, double-blind, double-dummy trial.

While the results also showed an increased risk for major bleeding among those who received apixaban, compared with their counterparts taking aspirin, the researchers point out that “strokes involve permanent loss of brain tissue, whereas major bleeding is usually reversible, with most patients having complete recovery.” 

The ARTESIA trial, which was published in The New England Journal of Medicine, involved 4012 patients (36% women), aged an average of 77 years, with asymptomatic AF that lasted between 6 minutes and 24 hours, as detected by implanted, continuous cardiac monitoring devices. Participants all had a CHA₂DS₂-VASc score of 3 or higher (mean 3.9) where, on a score of 0–9, a higher score denotes greater stroke risk.

In all, 2015 patients were randomly assigned to receive apixaban 5 mg twice daily (reduced to 2.5 mg twice daily where indicated) and 1997 to receive aspirin 81 mg/day. 

After a median follow-up of 3.5 years, stroke and systemic embolism occurred in 55 (0.78% per person–year) and 86 (1.24% per person–year) of patients receiving apixaban and aspirin, respectively, with a statistically significant hazard ratio for the primary endpoint of 0.63 in favor of apixaban use.

These stroke events were assessed as being disabling or fatal in 33% and 43% of the apixaban and aspirin groups, respectively, giving a significant 49% reduction in the risk of these outcomes with apixaban, report Jeff Healey, from McMaster University in Hamilton, Ontario, Canada, and colleagues.

The team also examined the risk for major bleeding in the cohort and found it was a significant 1.8 times higher with apixaban than aspirin, at 1.71% and 0.94% per person–year, respectively. Fatal major bleeding events occurred in a corresponding five and eight patients, but the researchers note that “most bleeding events responded to supportive care.”

Healey and colleagues thus conclude that “on the basis of the considerably greater severity of the stroke events prevented than the bleeding events caused, we believe that these findings favor consideration of the use of oral anticoagulation for patients with risk factors for stroke in whom subclinical atrial fibrillation develops.”

In an accompanying editorial, Emma Svennberg from Karolinska University Hospital in Stockholm, Sweden, supports the conclusion, adding that the fact aspirin was the comparator treatment in ARTESIA is important to note because the relative risk for bleeding “might be lower than that in a population untreated with aspirin.” 

She concludes that: “Going forward, we must balance the increased bleeding risks with the risk for disabling strokes. 

“In patients with subclinical atrial fibrillation, vital components of care management include shared decision making before oral anticoagulant treatment, management of modifiable bleeding risks and coexisting conditions, and close monitoring of progression to clinical atrial fibrillation.”

The findings were also presented at the AHA Scientific Sessions 2023 in Philadelphia, Pennsylvania, USA.

medwireNews is an independent medical news service provided by Springer Healthcare Ltd. © 2023 Springer Healthcare Ltd, part of the Springer Nature Group

New Engl J Med 2023; doi:10.1056/NEJMoa2310234
New Engl J Med 2023; doi:10.1056/NEJMe2311558


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