Apixaban versus aspirin for stroke prevention in people with subclinical atrial fibrillation and a history of stroke or transient ischaemic attack: subgroup analysis of the ARTESiA randomised controlled trial.

Summary

In a prespecified subgroup of ARTESiA, patients with device-detected subclinical atrial fibrillation and prior stroke/TIA derived a large absolute reduction (7% over 3.5 years) in stroke/systemic embolism with apixaban versus aspirin, albeit with a 3% absolute increase in major bleeding. The benefit was smaller (1%) in those without prior cerebrovascular events.

Key Findings

• In subclinical AF with prior stroke/TIA (n=346), apixaban reduced stroke/systemic embolism vs aspirin (HR 0.40; annual 1.20% vs 3.14%).
• Absolute risk reduction at 3.5 years was 7% with apixaban in those with prior stroke/TIA, vs 1% in those without.
• Major bleeding increased with apixaban; absolute increase at 3.5 years was 3% (prior stroke/TIA) and 1% (no prior stroke/TIA).

Clinical Implications

For patients with device-detected subclinical AF and prior stroke/TIA, apixaban should be considered for secondary stroke prevention after individualized bleeding risk assessment and shared decision-making.

Limitations

• Subgroup analysis, despite prespecification, may have limited power and generalizability
• Increased major bleeding necessitates careful patient selection and risk–benefit discussion

Future Directions

Define thresholds of subclinical AF burden and clinical profiles that optimize net benefit of anticoagulation; comparative effectiveness across DOACs; biomarker- or imaging-guided selection.