Risk of Stroke or Systemic Embolism According to Baseline Frequency and Duration of Subclinical Atrial Fibrillation: Insights From the ARTESiA Trial

William F McIntyre; Alexander P Benz; Jeff S Healey; Stuart J Connolly; Mu Yang; Shun Fu Lee; Thalia S Field; Marco Alings; J Benezet-Mazuecos; Giuseppe Boriani; J Cosedis Nielsen; Michael R Gold; Francesco Pergolini; Taya V Glotzer; Christopher B Granger; Renato D Lopes

doi:10.1161/CIRCULATIONAHA.124.069903

Risk of Stroke or Systemic Embolism According to Baseline Frequency and Duration of Subclinical Atrial Fibrillation: Insights From the ARTESiA Trial

Circulation. 2024 Sep 4. doi: 10.1161/CIRCULATIONAHA.124.069903. Online ahead of print.

Authors

William F McIntyre¹, Alexander P Benz², Jeff S Healey², Stuart J Connolly², Mu Yang³, Shun Fu Lee¹, Thalia S Field⁴, Marco Alings⁵, J Benezet-Mazuecos⁶, Giuseppe Boriani⁷, J Cosedis Nielsen⁸, Michael R Gold⁹, Francesco Pergolini¹⁰, Taya V Glotzer¹¹, Christopher B Granger¹², Renato D Lopes¹³

Affiliations

¹ Population Health Research Institute, Hamilton, Canada. (W.M., S.F.L.).
² McMaster University (A.B., J.H., S.C.), Hamilton, Canada.
³ University of Waterloo, Canada (M.Y.).
⁴ Vancouver Stroke Program, University of British Columbia, Canada (T.F.).
⁵ Working Group on Cardiovascular Research (M.A.).
⁶ Hospital Universitario La Luz, Madrid, Spain (J.B.-M.).
⁷ University of Modena and Reggio Emilia, Modena, Italy (G.B.).
⁸ Aarhus University Hospital, Denmark (J.N.).
⁹ Medical University of South Carolina, Charleston (M.G.).
¹⁰ Maggiore Hospital, Bologna, Italy (F.P.).
¹¹ Hackensack University Medical Center, NJ (T.G.).
¹² Duke University (C.G.), Durham, NC.
¹³ Duke Clinical Research Institute (R.L.).

PMID: 39229707
DOI: 10.1161/CIRCULATIONAHA.124.069903

Abstract

Background: In the ARTESiA trial (Apixaban for the Reduction of Thromboembolism in Patients With Device-Detected Subclinical Atrial Fibrillation), apixaban, compared with aspirin, reduced stroke or systemic embolism in patients with device-detected subclinical atrial fibrillation (SCAF). Clinical guidelines recommend considering SCAF episode duration when deciding whether to prescribe oral anticoagulation for this population.

Methods: We performed a retrospective cohort study in ARTESiA. Using Cox regression adjusted for CHA₂DS₂-VASc score and treatment allocation (apixaban or aspirin), we assessed frequency of SCAF episodes and duration of the longest SCAF episode in the 6 months before randomization as predictors of stroke risk and of apixaban treatment effect.

Results: Among 3986 patients with complete baseline SCAF data, 703 (17.6%) had no SCAF episode ≥6 minutes in the 6 months before enrollment. Among 3283 patients (82.4%) with ≥1 episode of SCAF ≥6 minutes in the 6 months before enrollment, 2542 (77.4%) had up to 5 episodes, and 741 (22.6%) had ≥6 episodes. The longest episode lasted <1 hour in 1030 patients (31.4%), 1 to <6 hours in 1421 patients (43.3%), and >6 hours in 832 patients (25.3%). Higher baseline SCAF frequency was not associated with increased risk of stroke or systemic embolism: 1.1% for 1 to 5 episodes versus 1.2%/patient-year for ≥6 episodes (adjusted hazard ratio, 0.89 [95% CI, 0.59-1.34]). In an exploratory analysis, patients with previous SCAF but no episode ≥6 minutes in the 6 months before enrollment had a lower risk of stroke or systemic embolism than patients with at least one episode during that period (0.5% versus 1.1%/patient-year; adjusted hazard ratio, 0.48 [95% CI, 0.27-0.85]). The frequency of SCAF did not modify the reduction in stroke or systemic embolism with apixaban (P_interaction=0.1). The duration of the longest SCAF episode in the 6 months before enrollment was not associated with the risk of stroke or systemic embolism during follow-up (<1 hour: 1.0%/patient-year [reference]; 1-6 hours: 1.2%/patient-year [adjusted hazard ratio, 1.27 (95% CI, 0.85-1.90)]; >6 hours: 1.0%/patient-year [adjusted hazard ratio, 1.02 (95% CI, 0.63-1.66)]). SCAF duration did not modify the reduction in stroke or systemic embolism with apixaban (P_trend=0.1).

Conclusions: In ARTESiA, baseline SCAF frequency and longest episode duration were not associated with risk of stroke or systemic embolism and did not modify the effect of apixaban on reduction of stroke or systemic embolism.

Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01938248.

Keywords: anticoagulants; atrial fibrillation; defibrillators; stroke.

Associated data

ClinicalTrials.gov/NCT01938248