Arrhythmias & electrophysiologySecondary analysis

Atrial Fibrillation Screening According to Genetic Risk

J Am Coll CardiolPublished

  • Secondary analysis of the LOOP randomised trial
  • prespecified post hoc analysis

Authors' conclusion

ILR screening for AF was associated with a significant reduction in stroke/SE in individuals with higher genetic risk of AF but not in those with lower genetic risk.

Study context

Population
Atrial fibrillation (AF)-naive individuals aged ≥70 years with stroke risk factors and available genetic datarandomized 1:3
Participants
5,656 individuals
Comparison
Implantable loop recorder (ILR) screening vs usual care, by polygenic risk score for AF
Primary endpoint
Stroke or systemic embolism

Primary result

As reported in the abstract

Stroke/SE by PRSAF · median follow-up 5.4 years
ILR vs Usual careHazard ratio (95% CI)P value
PRSAF ≥median
0.65(0.43–0.97)
P = 0.036
PRSAF <median
1.06(0.72–1.57)
P = 0.75

Further findings

OutcomeEstimateP value
AF diagnosis by PRSAFHR 1.20 (95% CI 1.13–1.28)P < 0.001
≥1 AF episode lasting ≥24 hours (ILR-detected AF)OR 1.35 (95% CI 1.02–1.78)P = 0.037
  • AF diagnosis by PRS for AF (PRSAF): 969 participants (17.1%) received a diagnosis of AF

Safety

OutcomeHR (95% CI)P value
Major bleeding by PRSAF · PRSAF <median1.71 (1.12–2.64)P = 0.011
  • Major bleeding by PRSAF: Pinteraction = 0.036
  • Major bleeding by PRSAF: 206 (3.6%) had major bleeding

Original publication

Atrial Fibrillation Screening According to Genetic Risk. J Am Coll Cardiol. Published 29 October 2025. doi:10.1016/j.jacc.2025.09.024

Summarised from the published abstract; every number is checked against it