Research Highlights:
Embargoed until 8:45 a.m. ET, Sunday, Nov. 12, 2023
PHILADELPHIA, Nov. 12, 2023 — The anti-clotting medication apixaban reduced the rate of stroke and blood clots, among adults with implanted heart devices experiencing short bouts of asymptomatic, irregular heart rhythms compared to adults who took aspirin, according to late-breaking science presented today at the American Heart Association’s Scientific Sessions 2023 . The meeting, Nov. 11-13, in Philadelphia, is a premier global exchange of the latest scientific advancements, research and evidence-based clinical practice updates in cardiovascular science. The full manuscript is also simultaneously published today in The New England Journal of Medicine.
The medication was associated with major bleeding; however, it was not life-threatening.
Atrial fibrillation , or AFib, is an irregular heartbeat that can lead to blood clots, stroke , heart failure or other heart-related complications. It can occur without symptoms or be so brief that it is difficult to detect. Subclinical atrial fibrillation is brief, asymptomatic AFib that is detected by pacemakers, implantable defibrillators and cardiac monitors that record people’s heart rates continuously and detect these short bouts of irregular heartbeats.
Previous research has indicated that treatment with oral anti-clotting medications (also known as anticoagulants) may prevent up to two-thirds of strokes in people diagnosed with atrial fibrillation. However, anti-clotting medications including apixaban cause an increased risk of major bleeding, including blood in stool or in urine, and/or trauma-related bleeding.
“We have observed in previous research that the magnitude of stroke risk associated with short duration, asymptomatic, subclinical atrial fibrillation was lower than what was seen in people with longer-lasting symptomatic atrial fibrillation,” said study author Jeff Healey, M.D., M.S., cardiology division director and professor of medicine at McMaster University in Hamilton, Ontario, Canada. “So that’s a different risk-benefit consideration for prescribing anticoagulants.”
This phase 4 clinical trial, called “Apixaban for the Reduction of Thrombo-Embolism in patients with device-detected Subclinical Atrial fibrillation trial (ARTESIA),” examined the risk-benefit considerations of treating asymptomatic atrial fibrillation. Researchers enrolled more than 4,000 adults from 16 countries in North America and Europe who had an implanted pacemaker, defibrillator or cardiac monitor that detected asymptomatic atrial fibrillation.
Half of the participants were randomly assigned to receive an anticoagulant (the standard treatment for patients with stroke risk factors who have clinical atrial fibrillation); specifically, 5 mg of apixaban, twice daily or 2.5 mg twice daily in patients meeting a pre-set criteria for dose reduction such as being over age 80 or weighing less than 132 pounds). The other half of the participants received 81 mg of aspirin daily. Neither participants nor researchers knew which medication participants were taking. Researchers monitored study participants for an average of 3.5 years for stroke, blood clots and/or major bleeding.
The investigation found:
“Currently, there is no consistent guidance on how to treat subclinical atrial fibrillation in people with implanted heart devices. I think the results of ARTESIA are strong enough to change the way we practice and lead to changes in management guidelines so that we recommend that many of these individuals who have subclinical AFib receive an anticoagulant,” Healy said. “The study’s findings will also help to address ongoing questions about the potential value of population-based screening for AFib.”
Future studies by these researchers and others will look further into tailoring therapy by determining if there are subgroups of people who are at higher or lower risk for stroke, blood clots and/or bleeding.
Of particular note, this study did not directly address the question of whether the millions of people with consumer technologies, including smart watches, smart rings and smart phones that can detect short-lasting episodes of atrial fibrillation, should be treated with an anti-clotting medication.
Among the study’s limitations are that only people with implanted heart devices were enrolled in the trial, and the approach to aspirin therapy changed somewhat during the years of the trial. Aspirin used to be a recommended therapy for stroke prevention in people with AFib, particularly those with lower risk, Healy explained. After the ARTESIA study was designed, this recommendation fell out of favor. As well, over the last 10 years, there has been a sharp decline in the combined use of aspirin on top of oral anticoagulants, as other studies have demonstrated no incremental benefit to aspirin, but a doubling in the rate of major bleeding.
Study details:
Co-authors, disclosures and funding sources are listed in the abstract.
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