- Question
- Does screening for atrial fibrillation with an implantable loop recorder, followed by anticoagulation if detected, prevent stroke in high-risk individuals?
- Design
- Open-label randomized trial at four centres in Denmark, with 1:3 allocation to implantable loop recorder (ILR) monitoring or usual care. A total of 6004 participants were included, with a median follow-up of 64.5 months and no loss to follow-up.
- Population
- Individuals aged 70 to 90 years without known atrial fibrillation and with at least one additional stroke risk factor (hypertension, diabetes, previous stroke, or heart failure).
- Intervention
- Implantation of a loop recorder with continuous ECG monitoring; anticoagulation was recommended if atrial fibrillation episodes lasting 6 minutes or longer were detected.
- Control
- Usual care, with follow-up by the general practitioner.
- Primary outcome
- Time to first stroke or systemic arterial embolism.
- Results
- The primary outcome occurred in 67 participants (4.5%) in the ILR group and 251 (5.6%) in the control group (HR 0.80; 95% CI 0.61-1.05; p=0.11), a non-significant difference. Atrial fibrillation was diagnosed in 31.8% of the ILR group versus 12.2% of controls (HR 3.17; 95% CI 2.81-3.59).
- Safety
- Major bleeding occurred in 65 participants (4.3%) in the ILR group and 156 (3.5%) in the control group (HR 1.26; 95% CI 0.95-1.69; p=0.11).
- Conclusion
- ILR screening tripled atrial fibrillation detection and anticoagulation initiation but did not significantly reduce stroke or systemic arterial embolism.
- Why it matters
- It questioned whether detecting all subclinical atrial fibrillation with continuous monitoring and anticoagulating is beneficial, suggesting that not all screen-detected atrial fibrillation warrants anticoagulation.
Card generated automatically with AI from the abstract of the original publication and the trial registry; every figure was checked against those sources. It may contain errors: verify the data at the source before using it for clinical decisions.
Generated on October 18, 2026