ABSTRACT NUMBER: ESOC2026A95 EARLY DETECTION OF ATRIAL FIBRILLATION IN PRIMARY CARE: POTENTIAL STROKE PREVENTION IMPACT FROM THE PREFATE STUDY

Abstract Background and aims Atrial fibrillation(AF) is the leading preventable cause of ischemic stroke. The PREFATE study aimed to assess the prevalence of device-detected AF(DDAF) in a high-risk primary care population and estimate the potential stroke prevention benefit achievable through early diagnosis and management. Methods This prospective cohort study(NCT05772806) included 149 patients aged 65–85 years at high risk of AF without prior diagnosis. Participants underwent 14 days of rhythm monitoring with the FibriCheck® app,baseline ECGs, and echocardiographic evaluation of left atrial(LA) function. Newly diagnosed AF cases were confirmed by ECG or Holter. The number needed to screen(NNS) to detect one new AF case and the estimated number of strokes potentially preventable through anticoagulation were calculated using current European risk models. Results New AF was diagnosed in 13 participants(8.7%), corresponding to an NNS of 12. Participants with positive FibriCheck® findings had a 71-fold higher probability of AF confirmation (post-test odds 87.7%). Echocardiographic markers of LA dysfunction (LA strain<26% and LA ejection fraction<50%) and an MVP-ECG score≥4 were strong predictors of AF. Assuming oral anticoagulation reduces stroke risk by ~65%,and given an average CHA₂DS₂-VA score of 3.9, early detection in similar high-risk populations could prevent approximately 1 stroke per 18 patients screened, equating to 55 preventable strokes per 1,000 individuals monitored annually. Conclusions Systematic AF screening in primary care using digital tools such as FibriCheck®, combined with ECG and echocardiography-based risk stratification, could substantially reduce AF-related stroke burden in the community. Conflict of interest Nothing to disclose